A038751 A variant of the recurrence for A001190.

0, 1, 1, 0, 1, 1, 2, 3, 6, 9, 18, 30, 60, 105, 210, 381, 765, 1425, 2868, 5454, 11004, 21210, 42930, 83673, 169851, 333843, 679602, 1345476, 2745636, 5467275, 11182365, 22379895, 45866418, 92180781, 189275955, 381831396, 785328636

Offset: 0

Author

N. J. A. Sloane, May 03 2000

Keywords

• nonn

Comments

See Maple program for the recurrence.

Crossrefs

Cf. A001190, A038750.

Programs

Maple

A038751 := proc(n) option remember; local s,k; if n<=1 then RETURN(n); else s := 0; if n mod 2 = 0 then s := A038751(n/2) * (A038751(n/2) + 1)/2; for k from 1 to n/2 - 1 do s := s + A038751(k) * A038751(n - k); od; RETURN(s); else for k from 1 to (n - 1)/2 - 1 do s := s + A038751(k) * A038751(n - k); od; RETURN(s); fi; fi; end;