A091347 a(n) = 6*4^n - 12*3^n + 7*2^n - 1.
0, 1, 15, 115, 675, 3451, 16275, 72955, 316275, 1340251, 5590035, 23054395, 94314675, 383578651, 1553331795, 6270493435, 25253701875, 101530450651, 407669649555, 1635323974075, 6555235693875, 26262769508251, 105176572911315, 421082805640315, 1685460823266675, 6745232212623451
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (10, -35, 50, -24).
Programs
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Mathematica
Table[6*4^n - 12*3^n + 7*2^n - 1, {n, 0, 25}] -
PARI
a(n) = sum(i=1, n, i!*i^3*stirling(n, i, 2)*(-1)^(n-i)); \\ Michel Marcus, Oct 21 2022
Formula
a(n) = Sum_{i=1..n} i!*i^3*Stirling2(n, i)*(-1)^(n-i).
Extensions
More terms from Michel Marcus, Oct 21 2022