OFFSET
4,5
COMMENTS
With offset 8 number of partitions of n, where the difference between the number of odd parts and the number of even parts is -4.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 4..1000
MAPLE
b:= proc(n, i, t) option remember; `if`(abs(t)>n, 0,
`if`(n=0, 1, `if`(i<1, 0, b(n, i-1, t)+
`if`(i>n, 0, b(n-i, i, t+(2*irem(i, 2)-1))))))
end:
a:= n-> b(n$2, -4):
seq(a(n), n=4..80);
MATHEMATICA
b[n_, i_, t_] := b[n, i, t] = If[Abs[t] > n, 0, If[n == 0, 1, If[i < 1, 0, b[n, i - 1, t] + If[i > n, 0, b[n - i, i, t + 2 Mod[i, 2] - 1]]]]];
a[n_] := b[n, n, -4];
a /@ Range[4, 80] (* Jean-François Alcover, Dec 10 2020, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 30 2014
STATUS
approved