|
| |
|
|
A187656
|
|
Convolution of the (signless) central Stirling numbers of the first kind (A187646).
|
|
0
|
|
|
|
1, 2, 23, 472, 14109, 557138, 27417263, 1617536576, 111304630793, 8752522524930, 774271257457719, 76102169738598232, 8227653697751043061, 970337814111625277394, 123968202132756025685151, 17055359730313188973301568
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Table of n, a(n) for n=0..15.
|
|
|
FORMULA
|
a(n) = sum(s(2k,k)s(2n-2k,n-k)),k=0..n)
|
|
|
MAPLE
|
seq(sum(abs(combinat[stirling1](2*k, k))*abs(combinat[stirling1](2*(n-k), n-k)), k=0..n), n=0..12);
|
|
|
MATHEMATICA
|
Table[Sum[Abs[StirlingS1[2k, k]]Abs[StirlingS1[2n - 2k, n - k]], {k, 0, n}], {n, 0, 15}]
|
|
|
PROG
|
(Maxima) makelist(sum(abs(stirling1(2*k, k))*abs(stirling1(2*n-2*k, n-k)), k, 0, n), n, 0, 12);
|
|
|
CROSSREFS
|
Cf. A187646
Sequence in context: A119774 A074649 A134355 * A054260 A053160 A167416
Adjacent sequences: A187653 A187654 A187655 * A187657 A187658 A187659
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
Emanuele Munarini, Mar 12 2011
|
|
|
STATUS
|
approved
|
| |
|
|
