|
| |
|
|
A100034
|
|
Bisection of A000081 (even part).
|
|
4
|
|
|
|
0, 1, 4, 20, 115, 719, 4766, 32973, 235381, 1721159, 12826228, 97055181, 743724984, 5759636510, 45007066269, 354426847597, 2809934352700, 22409533673568, 179655930440464, 1447023384581029, 11703780079612453, 95020085893954917, 774088023431472074
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,3
|
|
|
LINKS
|
Alois P. Heinz, Table of n, a(n) for n = 0..400
|
|
|
MAPLE
|
with(numtheory):
b:= proc(n) option remember; local d, j; `if`(n<2, n,
(add(add(d*b(d), d=divisors(j))*b(n-j), j=1..n-1))/(n-1))
end:
a:= n-> b(2*n):
seq(a(n), n=0..50); # Alois P. Heinz, May 16 2013
|
|
|
MATHEMATICA
|
b[n_] := b[n] = If[n <= 1, n, Sum[Sum[d*b[d], {d, Divisors[j]}]*b[n-j], {j, 1, n-1}]/(n-1)]; a[n_] := b[2*n]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Mar 19 2014, after Alois P. Heinz *)
|
|
|
CROSSREFS
|
Cf. A000081, A100427, A299098.
Sequence in context: A316298 A291531 A171802 * A341919 A192924 A258664
Adjacent sequences: A100031 A100032 A100033 * A100035 A100036 A100037
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
N. J. A. Sloane, Nov 20 2004
|
|
|
EXTENSIONS
|
More terms from Joshua Zucker, May 12 2006
|
|
|
STATUS
|
approved
|
| |
|
|
