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A152995 Twice 11-gonal numbers: a(n) = n*(9*n-7). 2
0, 2, 22, 60, 116, 190, 282, 392, 520, 666, 830, 1012, 1212, 1430, 1666, 1920, 2192, 2482, 2790, 3116, 3460, 3822, 4202, 4600, 5016, 5450, 5902, 6372, 6860, 7366, 7890, 8432, 8992, 9570, 10166, 10780, 11412, 12062, 12730, 13416, 14120 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..40.

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

FORMULA

a(n) = 9*n^2 - 7*n = A051682(n)*2.

a(n) = a(n-1) + 18*n - 16 (with a(0)=0). - Vincenzo Librandi, Nov 27 2010

a(0)=0, a(1)=2, a(2)=22, a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Harvey P. Dale, Nov 02 2011

MATHEMATICA

s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 2, 6!, 18}]; lst (* Vladimir Joseph Stephan Orlovsky, Apr 02 2009 *)

Table[n(9n-7), {n, 0, 40}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 2, 22}, 40] (* Harvey P. Dale, Nov 02 2011 *)

PROG

(MAGMA) [ n*(9*n-7): n in [0..50] ];

(PARI) a(n)=n*(9*n-7) \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Cf. A051682 (11-gonal numbers).

Cf. A226488.

Sequence in context: A156454 A168669 A271883 * A273366 A053940 A156480

Adjacent sequences:  A152992 A152993 A152994 * A152996 A152997 A152998

KEYWORD

easy,nonn

AUTHOR

Omar E. Pol, Dec 22 2008

STATUS

approved

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Last modified August 18 15:00 EDT 2019. Contains 326106 sequences. (Running on oeis4.)