OFFSET
0,22
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = A025152(n-6), n>6. - R. J. Mathar, Jul 31 2008
G.f.: x^6*Product_{j>=7} (1+x^j). - R. J. Mathar, Jul 31 2008
G.f.: Sum_{k>=1} x^(k*(k + 11)/2) / Product_{j=1..k-1} (1 - x^j). - Ilya Gutkovskiy, Nov 24 2020
MAPLE
b:= proc(n, i) option remember;
`if`(n=0, 1, `if`((i-6)*(i+7)/2<n, 0,
add(b(n-i*j, i-1), j=0..min(1, n/i))))
end:
a:= n-> `if`(n<6, 0, b(n-6$2)):
seq(a(n), n=0..100); # Alois P. Heinz, Feb 07 2014
MATHEMATICA
b[n_, i_] := b[n, i] = If[n == 0, 1, If[(i-6)*(i+7)/2 < n, 0, Sum[b[n - i*j, i - 1], {j, 0, Min[1, n/i]}]]]; a[n_] := If[n < 6, 0, b[n-6, n-6]]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jun 24 2015, after Alois P. Heinz *)
Join[{0}, Table[Count[Last /@ Select[IntegerPartitions@n, DeleteDuplicates[#] == # &], 6], {n, 66}]] (* Robert Price, Jun 13 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved