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”).

A071230
a(n) = n*(6*n^2 - 7*n + 3)/2.
1
0, 1, 13, 54, 142, 295, 531, 868, 1324, 1917, 2665, 3586, 4698, 6019, 7567, 9360, 11416, 13753, 16389, 19342, 22630, 26271, 30283, 34684, 39492, 44725, 50401, 56538, 63154, 70267, 77895, 86056, 94768, 104049, 113917, 124390, 135486
OFFSET
0,3
REFERENCES
T. A. Gulliver, Sequences from Arrays of Integers, Int. Math. Journal, Vol. 1, No. 4, pp. 323-332, 2002.
FORMULA
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
From G. C. Greubel, Aug 05 2024: (Start)
G.f.: x*(1 + 9*x + 8*x^2)/(1-x)^4.
E.g.f.: (1/2)*x*(2 + 11*x + 6*x^2)*exp(x). (End)
MATHEMATICA
Table[n*(6*n^2 - 7*n + 3)/2, {n, 0, 40}]
PROG
(Magma) [n*(6*n^2-7*n+3)/2: n in [0..50]]; // Vincenzo Librandi, Jun 14 2011
(SageMath)
def A071230(n): return n*(6*n^2 -7*n +3)//2
[A071230(n) for n in range(51)] # G. C. Greubel, Aug 05 2024
CROSSREFS
Cf. A071229.
Sequence in context: A358166 A372756 A195024 * A027000 A198160 A029531
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jun 11 2002
EXTENSIONS
More terms from Robert G. Wilson v, Jun 12 2002
STATUS
approved