OFFSET
0,2
LINKS
Paolo Xausa, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (15,-66,80).
FORMULA
From Vincenzo Librandi, Mar 16 2011: (Start)
a(n) = 15*a(n-1) - 66*a(n-2) + 80*a(n-3), n >= 3.
a(n) = 13*a(n-1) - 40*a(n-2) + 2^n, n >= 2. (End)
a(n) = 4*8^(n+1)/9 + 2^(n+1)/9 - 5^(n+2)/9. - R. J. Mathar, Mar 18 2011
From Seiichi Manyama, May 04 2025: (Start)
a(n) = Sum_{k=0..n} 3^k * 2^(n-k) * binomial(n+2,k+2) * Stirling2(k+2,2).
a(n) = Sum_{k=0..n} (-3)^k * 8^(n-k) * binomial(n+2,k+2) * Stirling2(k+2,2). (End)
E.g.f.: exp(2*x)*(2 - 25*exp(3*x) + 32*exp(6*x))/9. - Stefano Spezia, May 04 2025
MATHEMATICA
LinearRecurrence[{15, -66, 80}, {1, 15, 159}, 25] (* Paolo Xausa, May 10 2026 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved
