OFFSET
0,2
COMMENTS
This is the column k=2 sequence of the Riordan triangle A248156 without the leading two zeros.
LINKS
Index entries for linear recurrences with constant coefficients, signature (-4,-6,-4,-1).
FORMULA
O.g.f.: (1 - 2*x^2)/(1 + x)^4 = -1/(1 + x)^4 + 4/(1 + x)^3 -2/(1 + x)^2.
a(n) = (-1)^n*(n+1)*(6 + 7*n - n^2)/3!, n >= 0.
a(n) = -4*(a(n-1) + a(n-3)) - 6*a(n-2) - a(n-4), n >= 4, with a(0) =1, a(1) = -4, a(2) = 8 and a(3) = -12.
a(n)+a(n+1) = A248158(n+1). - R. J. Mathar, Mar 13 2021
MAPLE
A248159:=n->(-1)^(n+1)*(n+1)*(n^2-7*n-6)/3!: seq(A248159(n), n=0..50); # Wesley Ivan Hurt, Oct 07 2014
MATHEMATICA
Table[(-1)^(n + 1)*(n + 1)*(n^2 - 7*n - 6)/3!, {n, 0, 50}] (* Wesley Ivan Hurt, Oct 07 2014 *)
PROG
(Magma) [(-1)^(n+1)*(n+1)*(n^2-7*n-6)/Factorial(3) : n in [0..50]]; // Wesley Ivan Hurt, Oct 07 2014
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang, Oct 07 2014
STATUS
approved