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A201732
a(n) = [x^n/n!] (1/x) * log( (n+1 - n*exp(x)) / (n+2 - (n+1)*exp(x)) ).
1
1, 2, 18, 386, 15150, 946082, 86148762, 10776331778, 1773210244230, 371367615732002, 96462262816769586, 30433572793375652738, 11463680237091180885150, 5081782052880868302982562, 2618864991559576227420716490, 1552537179057766207300655437826
OFFSET
0,2
COMMENTS
The function log((n+1 - n*exp(x))/(n+2 - (n+1)*exp(x))) equals the (n+1)-th iteration of log(1/(2-exp(x)), the e.g.f. of A000629 (with offset 1), where A000629(n) is the number of necklaces of partitions of n+1 labeled beads.
FORMULA
a(n) = A201731(n+1) / (n+1).
PROG
(PARI) {a(n)=n!*polcoeff((1/x)*log((n+1 - n*exp(x+O(x^(n+2))))/(n+2 - (n+1)*exp(x+O(x^(n+2))))), n)}
CROSSREFS
Sequence in context: A336217 A226837 A152684 * A374278 A260656 A141074
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Dec 04 2011
STATUS
approved