OFFSET
0,3
COMMENTS
All odd elements are in blocks with an odd index and all even elements are in blocks with an even index. Blocks are ordered with increasing least elements.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..660
Wikipedia, Partition of a set
EXAMPLE
a(4) = 9 = 2 + 3 + 4: 13|24, 1|24|3, 1|2|3|4.
a(5) = 24 = 2 + 3 + 3 + 3 + 4 + 4 + 5: 135|24, 13|24|5, 15|24|3, 1|24|35, 15|2|3|4, 1|2|35|4, 1|2|3|4|5.
MAPLE
b:= proc(n, m, t) option remember; `if`(n=0, m, add(
`if`(irem(j, 2)=t, b(n-1, max(m, j), 1-t), 0), j=1..m+1))
end:
a:= n-> b(n, 0, 1):
seq(a(n), n=0..30);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 16 2023
STATUS
approved