0,5

A038750 := proc(n) option remember; local s, k; if n<=1 then RETURN(n); elif n <=3 then RETURN(1); else s := 0; if n mod 2 = 0 then s := A038750(n/2)*(A038750(n/2)+1)/2; for k from 1 to n/2-1 do s := s+A038750(k)*A038750(n-k); od; RETURN(s); else for k from 1 to (n-1)/2-1 do s := s+A038750(k)*A038750(n-k); od; RETURN(s); fi; fi; end;

Cf. A001190, A038751.

Sequence in context: A145344 A034438 A079280 this_sequence A074476 A011021 A077232

Adjacent sequences: A038747 A038748 A038749 this_sequence A038751 A038752 A038753

nonn

N. J. A. Sloane (njas(AT)research.att.com), May 03 2000