login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A069174 Centered 23-gonal numbers. 4
1, 24, 70, 139, 231, 346, 484, 645, 829, 1036, 1266, 1519, 1795, 2094, 2416, 2761, 3129, 3520, 3934, 4371, 4831, 5314, 5820, 6349, 6901, 7476, 8074, 8695, 9339, 10006 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Ivan Panchenko, Table of n, a(n) for n = 1..1000

E. Weisstein, Centered Polygonal Numbers

Index entries for sequences related to centered polygonal numbers

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

a(n) = (23*n^2 - 23*n + 2)/2.

a(n) = 23*n+a(n-1)-23 (with a(1)=1). - Vincenzo Librandi, Aug 08 2010

MATHEMATICA

FoldList[#1 + #2 &, 1, 23 Range@ 45] (* Robert G. Wilson v, Feb 02 2011 *)

PROG

(PARI) a(n)=(23*n^2-23*n+2)/2 \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Cf. centered polygonal numbers listed in A069190.

Sequence in context: A043934 A087406 A051876 * A124717 A126378 A006352

Adjacent sequences:  A069171 A069172 A069173 * A069175 A069176 A069177

KEYWORD

nonn,easy

AUTHOR

Terrel Trotter, Jr., Apr 09 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified November 18 10:18 EST 2017. Contains 294887 sequences.