A331918 Number of compositions (ordered partitions) of n into distinct odd squares.

1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0, 1, 2, 6, 24, 0, 0, 0, 0, 0, 2

Offset: 0

Author

Ilya Gutkovskiy, Feb 01 2020

Keywords

• nonn
• look

Examples

			a(35) = 6 because we have [25, 9, 1], [25, 1, 9], [9, 25, 1], [9, 1, 25], [1, 25, 9] and [1, 9, 25].
		

Links

• Robert Israel, Table of n, a(n) for n = 0..10000
• Index entries for sequences related to compositions
• Index entries for sequences related to sums of squares

Crossrefs

Cf. A006456, A016754, A167661, A167700, A280863, A331844.

Programs

Maple

N:= 200: # for a(0)..a(N)
G:= mul(1+t*x^(i^2),i=1..floor(sqrt(N)),2):
F:= proc(n) local R, k, v;
  R:= coeff(G,x,n);
  add(k!*coeff(R,t,k),k=1..degree(R,t))
end proc:
F(0):= 1:
map(F, [$0..N]); # Robert Israel, Feb 03 2020