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A181509 a(1) = 2, a(n) = (n-th-even n^3) - (sum of previous terms) 1
2, 6, 56, 152, 296, 488, 728, 1016, 1352, 1736, 2168, 2648, 3176, 3752, 4376, 5048, 5768, 6536, 7352, 8216, 9128, 10088, 11096, 12152, 13256, 14408, 15608, 16856, 18152, 19496, 20888, 22328, 23816, 25352, 26936, 28568, 30248, 31976, 33752 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

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

FORMULA

a(n) = 56-72*n+24*n^2, n>2. a(n) = (2*n-2)^3-sum_{i=1..n-1} a(i). [From R. J. Mathar, Nov 01 2010]

For n>2, a(1)=56, a(2)=152, a(3)=296, a(n)=3*a(n-1)-3*a(n-2)+a(n-3) [From Harvey P. Dale, May 05 2011]

G.f.: 2*x*(22*x^2+x^4+1)/(1-x)^3. - R. J. Mathar, Aug 26 2011

a(n)=8*A003215(n-2) for n>2. - J. M. Bergot, Aug 21 2013

MATHEMATICA

Join[{2, 6}, Table[56-72n+24n^2, {n, 3, 42}]] (* or *) Join[{2, 6}, LinearRecurrence[{3, -3, 1}, {56, 152, 296}, 40]] (* Harvey P. Dale, May 05 2011 *)

CROSSREFS

Cf. A000578.

Sequence in context: A179389 A084123 A193473 * A213026 A074023 A000146

Adjacent sequences:  A181506 A181507 A181508 * A181510 A181511 A181512

KEYWORD

easy,nonn

AUTHOR

Giovanni Teofilatto, Oct 25 2010

EXTENSIONS

Corrected (replaced 2 and 4 by a 6 = 8-2) by R. J. Mathar, Nov 01 2010

STATUS

approved

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Last modified August 20 09:56 EDT 2019. Contains 326143 sequences. (Running on oeis4.)