Centered decagonal number

Centered decagonal number

A centered decagonal number is a centered figurate number that represents a decagon with a dot in the center and all other dots surrounding the center dot in successive decagonal layers. The centered decagonal number for n is given by the formula Thus, the first few centered decagonal numbers are 1, 11, 31, 61, 101, 151, 211, 281, 361, 451, 551, 661, 781, 911, 1051, ... (sequence in the OEIS) Another consequence of this relation to triangular numbers is the simple recurrence relation for centered decagonal numbers: where

Comment
enA centered decagonal number is a centered figurate number that represents a decagon with a dot in the center and all other dots surrounding the center dot in successive decagonal layers. The centered decagonal number for n is given by the formula Thus, the first few centered decagonal numbers are 1, 11, 31, 61, 101, 151, 211, 281, 361, 451, 551, 661, 781, 911, 1051, ... (sequence in the OEIS) Another consequence of this relation to triangular numbers is the simple recurrence relation for centered decagonal numbers: where
Depiction
Centered decagonal number.svg
Has abstract
enA centered decagonal number is a centered figurate number that represents a decagon with a dot in the center and all other dots surrounding the center dot in successive decagonal layers. The centered decagonal number for n is given by the formula Thus, the first few centered decagonal numbers are 1, 11, 31, 61, 101, 151, 211, 281, 361, 451, 551, 661, 781, 911, 1051, ... (sequence in the OEIS) Like any other centered k-gonal number, the nth centered decagonal number can be reckoned by multiplying the (n − 1)th triangular number by k, 10 in this case, then adding 1. As a consequence of performing the calculation in base 10, the centered decagonal numbers can be obtained by simply adding a 1 to the right of each triangular number. Therefore, all centered decagonal numbers are odd and in base 10 always end in 1. Another consequence of this relation to triangular numbers is the simple recurrence relation for centered decagonal numbers: where
Is primary topic of
Centered decagonal number
Label
enCentered decagonal number
Link from a Wikipage to an external page
dx.doi.org/10.1142/8188%7Ctitle=Figurate
Link from a Wikipage to another Wikipage
1 (number)
101 (number)
11 (number)
151 (number)
31 (number)
61 (number)
911 (number)
Category:Figurate numbers
Centered number
Continued fraction
Decagon
Decagonal number
Figurate number
File:Centered decagonal number.svg
Recurrence relation
Triangular number
SameAs
a612
Centered decagonal number
Centrerat dekagontal
Középpontos tízszögszámok
m.04j1xj
Nombre décagonal centré
Număr centrat decagonal
Numero decagonale centrato
Q1587812
Центрированное десятиугольное число
عدد ممركز عشاري
மையப்படுத்தப்பட்ட தசகோண எண்
Subject
Category:Figurate numbers
Thumbnail
Centered decagonal number.svg?width=300
WasDerivedFrom
Centered decagonal number?oldid=1117457459&ns=0
WikiPageLength
2088
Wikipage page ID
1216087
Wikipage revision ID
1117457459
WikiPageUsesTemplate
Template:Cite book
Template:Classes of natural numbers
Template:Figurate numbers
Template:OEIS
Template:Short description
Template:Use American English
Template:Use mdy dates