A005468 a(n) = 1 + a(floor(n/2))*a(ceiling(n/2)). (Formerly M0649)

1, 2, 3, 5, 7, 10, 16, 26, 36, 50, 71, 101, 161, 257, 417, 677, 937, 1297, 1801, 2501, 3551, 5042, 7172, 10202, 16262, 25922, 41378, 66050, 107170, 173890, 282310, 458330, 634350, 877970, 1215290, 1682210, 2335898, 3243602, 4504302, 6255002

Offset

1,2

References

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Alois P. Heinz, Table of n, a(n) for n = 1..5000

Maple

a:= proc(n) option remember; `if`(n<2, n,
      1+(t->a(t)*a(n-t))(iquo(n, 2)))
    end:
seq(a(n), n=1..50);  # Alois P. Heinz, Jun 24 2016

Prog

(PARI) v=vector(60); v[1]=1; for(k=2, 60, v[k]=v[k\2]*v[(k+1)\2]+1); v \\ Franklin T. Adams-Watters, Apr 22 2009

Crossrefs

Sequence in context: A234368 A052011 A278706 * A360464 A271063 A182521

Adjacent sequences: A005465 A005466 A005467 * A005469 A005470 A005471

Keyword

nonn,easy

Author

Colin Mallows

Extensions

More terms from Franklin T. Adams-Watters, Apr 22 2009

Status

approved