OFFSET
0,7
COMMENTS
Shifts 3 places left under inverse binomial transform.
FORMULA
a(0) = a(1) = 0, a(2) = 1; a(n) = Sum_{k=0..n-3} (-1)^k * binomial(n-3,k) * a(n-k-3).
MATHEMATICA
nmax = 31; A[_] = 0; Do[A[x_] = x^2 + x^3 A[x/(1 + x)]/(1 + x) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
a[0] = a[1] = 0; a[2] = 1; a[n_] := a[n] = Sum[(-1)^k Binomial[n - 3, k] a[n - k - 3], {k, 0, n - 3}]; Table[a[n], {n, 0, 31}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Feb 04 2022
STATUS
approved