A032320 Doubles (index 2+) under "EGJ" (unordered, element, labeled) transform.

2, 2, 12, 126, 1800, 33540, 757680, 20149290, 616940520, 21378058800, 827126546400, 35346832387020, 1653593623521840, 84055016334088800, 4613207941230688800, 271883701342581277950, 17125855412989960236600, 1148187688612239672677280, 81635218693106948988998880

Offset

1,1

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

C. G. Bower, Transforms (2)

Prog

(PARI) EGJ(v)={Vec(serlaplace(prod(k=1, #v, (1 + x^k/k! + O(x*x^#v))^v[k]))-1, -#v)}
seq(n)={my(v=[2]); for(i=2, n, v=concat(v, EGJ(concat(v, [0]))[i])); v} \\ Andrew Howroyd, Sep 21 2018
(PARI) seq(n)={my(p=(1+x)^2 + O(x*x^n)); for(k=2, n, p*=(1 + x^k/k! + O(x*x^n))^(k!*polcoef(p, k))); Vec(x+serlaplace(p-1)/2)} \\ Andrew Howroyd, Sep 21 2018

Crossrefs

Sequence in context: A013311 A303343 A087220 * A032227 A032069 A003090

Adjacent sequences: A032317 A032318 A032319 * A032321 A032322 A032323

Keyword

nonn

Author

Christian G. Bower

Extensions

Terms a(17) and beyond from Andrew Howroyd, Sep 21 2018

Status

approved