A171966 Number of partitions of n having no more odd than even parts.

1, 0, 1, 1, 2, 3, 4, 6, 8, 12, 15, 21, 28, 37, 49, 63, 83, 105, 138, 171, 223, 275, 353, 433, 551, 673, 846, 1031, 1282, 1558, 1922, 2327, 2848, 3440, 4179, 5032, 6078, 7293, 8763, 10482, 12534, 14943, 17797, 21146, 25090, 29719, 35138, 41493, 48908, 57578

Offset: 0

Author

Reinhard Zumkeller, Jan 21 2010

Keywords

• nonn

Comments

a(n) = A108949(n) + A045931(n) = A000041(n) - A108950(n).

a(n) = Sum_{k=-floor(n/2)+(n mod 2)..0} A240009(n,k). - Alois P. Heinz, Mar 30 2014

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A130780, A171967, A240009.

Programs

Maple

b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t<=0, 1, 0), `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, 0):
seq(a(n), n=0..80);  # Alois P. Heinz, Mar 30 2014

Mathematica

$RecursionLimit = 1000; b[n_, i_, t_] := b[n, i, t] = If[n == 0, If[t <= 0, 1, 0], 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, 0]; Table[a[n], {n, 0, 80}] (* Jean-François Alcover, Jun 30 2015, after Alois P. Heinz *)