OFFSET
0,11
COMMENTS
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..10000
FORMULA
a(n) = [x^n] Product_{i=1..floor(n/2)} 1 + x^i.
EXAMPLE
a(9) = 1 because we have: 2+3+4.
a(10) = 3 because we have: 1+4+5, 2+3+5, 1+2+3+4.
MAPLE
b:= proc(n, i) option remember; local m; m:= i*(i+1)/2;
`if`(n>m, 0, `if`(n=m, 1, b(n, i-1)+`if`(i>n, 0, b(n-i, i-1))))
end:
a:= n-> b(n, iquo(n, 2)):
seq(a(n), n=0..60); # Alois P. Heinz, May 25 2015
MATHEMATICA
Prepend[Table[nn = n; Coefficient[Series[Product[1 + x^i, {i, 1, nn/2}], {x, 0, nn}], x^n], {n, 1, 50}], 1]
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, May 24 2015
STATUS
approved