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A292692
a(n) = A258220(2n,n).
2
1, 6, 217, 13997, 1283817, 151778430, 21902350480, 3726598826676, 729894290301789, 161683308639785288, 39960246577221138239, 10900687898284398341055, 3253179971490906621196740, 1054372896576358319473872858, 368810384314446516250937494104
OFFSET
0,2
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..290 (terms 0..200 from Alois P. Heinz)
FORMULA
a(n) ~ c * d^n * n! / sqrt(n), where d = 25.81959672662517201... and c = 0.28310309251343879... - Vaclav Kotesovec, Dec 01 2017
Conjecture: d = (51*sqrt(17) - 107)/4. - Vaclav Kotesovec, Mar 17 2024
CROSSREFS
Cf. A258220.
Sequence in context: A229869 A234610 A041623 * A015477 A331477 A144658
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 20 2017
STATUS
approved