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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}]
LinearRecurrence[{4, -6, 4, -1}, {0, 1, 13, 54}, 40] (* Harvey P. Dale, May 29 2025 *)
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