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A033574
a(n) = (2*n+1)*(10*n+1).
2
1, 33, 105, 217, 369, 561, 793, 1065, 1377, 1729, 2121, 2553, 3025, 3537, 4089, 4681, 5313, 5985, 6697, 7449, 8241, 9073, 9945, 10857, 11809, 12801, 13833, 14905, 16017, 17169, 18361, 19593, 20865, 22177, 23529, 24921, 26353, 27825, 29337, 30889, 32481, 34113, 35785, 37497, 39249
OFFSET
0,2
FORMULA
From G. C. Greubel, Oct 12 2019: (Start)
G.f.: (1 + 30*x + 9*x^2)/(1-x)^3.
E.g.f.: (1 + 32*x + 20*x^2)*exp(x). (End)
MAPLE
seq((2*n+1)*(10*n+1), n=0..50); # G. C. Greubel, Oct 12 2019
MATHEMATICA
Table[(2*n+1)*(10*n+1), {n, 0, 50}] (* G. C. Greubel, Oct 12 2019 *)
PROG
(PARI) a(n)=(2*n+1)*(10*n+1) \\ Charles R Greathouse IV, Jun 17 2017
(Magma) [(2*n+1)*(10*n+1): n in [0..50]] # G. C. Greubel, Oct 12 2019
(Sage) [(2*n+1)*(10*n+1) for n in range(50)] # G. C. Greubel, Oct 12 2019
(GAP) List([0..50], n-> (2*n+1)*(10*n+1)); # G. C. Greubel, Oct 12 2019
CROSSREFS
Sequence in context: A008880 A370481 A045613 * A183446 A296125 A297429
KEYWORD
nonn,easy
EXTENSIONS
Terms a(33) onward added by G. C. Greubel, Oct 12 2019
STATUS
approved