|
| |
|
|
A098923
|
|
33-gonal numbers: n(31n-29)/2.
|
|
2
|
|
|
|
0, 1, 33, 96, 190, 315, 471, 658, 876, 1125, 1405, 1716, 2058, 2431, 2835, 3270, 3736, 4233, 4761, 5320, 5910, 6531, 7183, 7866, 8580, 9325, 10101, 10908, 11746, 12615, 13515, 14446, 15408, 16401, 17425, 18480, 19566, 20683, 21831, 23010
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,3
|
|
|
COMMENTS
|
Similar to 21-gonal and 15-gonal numbers (A051873, A051867).
|
|
|
LINKS
|
Daniel Starodubtsev, Table of n, a(n) for n = 0..10000
Index to sequences related to polygonal numbers
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
|
|
|
FORMULA
|
a(n) = n*(31*n-29)/2.
G.f.: x*(1+30*x)/(1-x)^3. - Bruno Berselli, Feb 04 2011
a(n) = 31*n + a(n-1) - 30 (with a(0)=0). - Vincenzo Librandi, Nov 16 2010
|
|
|
MATHEMATICA
|
Table[n(31n - 29)/2, {n, 0, 40}] (* Stefan Steinerberger, Feb 15 2006 *)
PolygonalNumber[33, Range[0, 40]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 02 2018 *)
|
|
|
PROG
|
(PARI) a(n)=n*(31*n-29)/2 \\ Charles R Greathouse IV, Oct 16 2015
|
|
|
CROSSREFS
|
Cf. A051867, A051873.
Sequence in context: A316799 A165378 A098938 * A044220 A044601 A195315
Adjacent sequences: A098920 A098921 A098922 * A098924 A098925 A098926
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Parthasarathy Nambi, Oct 18 2004
|
|
|
EXTENSIONS
|
More terms from Stefan Steinerberger, Feb 15 2006
|
|
|
STATUS
|
approved
|
| |
|
|
