login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A145980
a(n) = 29 + 73*n + 37*n^2.
2
29, 139, 323, 581, 913, 1319, 1799, 2353, 2981, 3683, 4459, 5309, 6233, 7231, 8303, 9449, 10669, 11963, 13331, 14773, 16289, 17879, 19543, 21281, 23093, 24979, 26939, 28973, 31081, 33263, 35519, 37849, 40253, 42731, 45283, 47909, 50609, 53383, 56231, 59153, 62149, 65219, 68363
OFFSET
0,1
FORMULA
a(n) = A061037(4n+2)+A061037(4n+3)+A061037(4n+4)+A061037(4n+5).
From R. J. Mathar, Oct 31 2008 (Start)
a(n) = 3*a(n-1)-3*a(n-2)+a(n-3).
G.f.: (29+52*x-7*x^2)/(1-x)^3. (End)
E.g.f.: (37*x^2 + 110*x + 29)*exp(x). - G. C. Greubel, Jan 29 2016
MATHEMATICA
LinearRecurrence[{3, -3, 1}, {29, 139, 323}, 50] (* G. C. Greubel, Jan 29 2016 *)
PROG
(Magma) [29+73*n+37*n^2: n in [0..40]]; // Vincenzo Librandi, Aug 07 2011
(PARI) a(n)=29+73*n+37*n^2 \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
Sequence in context: A118873 A247874 A162834 * A142622 A124957 A126416
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Oct 26 2008
EXTENSIONS
Indices in definition edited, extended beyond a(13) by R. J. Mathar, Oct 31 2008
STATUS
approved