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A131477
a(n) = ceiling(n^3/3).
1
0, 1, 3, 9, 22, 42, 72, 115, 171, 243, 334, 444, 576, 733, 915, 1125, 1366, 1638, 1944, 2287, 2667, 3087, 3550, 4056, 4608, 5209, 5859, 6561, 7318, 8130, 9000, 9931, 10923, 11979, 13102, 14292, 15552, 16885, 18291, 19773, 21334, 22974
OFFSET
0,3
FORMULA
From R. J. Mathar, Dec 19 2008: (Start)
G.f.: x*(1 + 3*x^2 + 2*x^3)/((1 - x)^4*(1 + x + x^2)).
a(n) = (A001093(n) - A049347(n))/3. (End)
a(n) = floor(n^3/3 + 2/3). - Bruno Berselli, Dec 21 2017
MATHEMATICA
Ceiling[Range[0, 50]^3/3] (* Harvey P. Dale, Oct 19 2013 *)
PROG
(Magma) [Ceiling(n^3/3) : n in [0..50]]; // Vincenzo Librandi, Oct 01 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mohammad K. Azarian, Jul 27 2007
STATUS
approved