A152777 7 times heptagonal numbers: 7*n*(5*n-3)/2.

0, 7, 49, 126, 238, 385, 567, 784, 1036, 1323, 1645, 2002, 2394, 2821, 3283, 3780, 4312, 4879, 5481, 6118, 6790, 7497, 8239, 9016, 9828, 10675, 11557, 12474, 13426, 14413, 15435, 16492, 17584, 18711, 19873, 21070, 22302, 23569

Offset

0,2

Comments

7 times 7-gonal numbers.

Links

Ivan Panchenko, Table of n, a(n) for n = 0..1000

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

Formula

a(n) = (35*n^2 - 21*n)/2 = A000566(n)*7.

a(n) = a(n-1)+35*n-28 (with a(0)=0). - Vincenzo Librandi, Dec 15 2010

Maple

A152777:=n->(35*n^2 - 21*n)/2; seq(A152777(n), n=0..100); # Wesley Ivan Hurt, Mar 04 2014

Mathematica

s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 7, 8!, 35}]; lst (* Vladimir Joseph Stephan Orlovsky, Apr 03 2009 *)

Prog

(Magma) [ 7*n*(5*n-3)/2 : n in [0..50] ]; // Wesley Ivan Hurt, Jun 09 2014
(PARI) a(n)=7*n*(5*n-3)/2 \\ Charles R Greathouse IV, Jun 17 2017

Crossrefs

Cf. A000566.

Sequence in context: A043131 A082701 A044145 * A003530 A262269 A163827

Adjacent sequences: A152774 A152775 A152776 * A152778 A152779 A152780

Keyword

easy,nonn

Author

Omar E. Pol, Dec 13 2008

Status

approved