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A270598 E.g.f.: Product_{k>0} (1 + tanh(x^k/k)). 7
1, 1, 1, 3, 14, 70, 364, 2548, 21104, 189936, 1830968, 20140648, 241712272, 3142259536, 43472528384, 652087925760, 10396900456448, 176747307759616, 3162885135453952, 60094817573625088, 1198006583353972736, 25158138250433427456, 551506339507727783936 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..448

FORMULA

E.g.f.: Product_{k>0} exp(x^k/k)/cosh(x^k/k).

a(n) ~ c * n!, where c = 1/A249673 = 1/Product_{k>=1} cosh(1/k) = 0.472485841489...

MATHEMATICA

nn=25; Range[0, nn]! * CoefficientList[Series[Product[1+Tanh[x^k/k], {k, 1, nn}], {x, 0, nn}], x]

CROSSREFS

Cf. A130263, A130268, A218504, A270597.

Sequence in context: A038213 A261207 A161939 * A001579 A327871 A006772

Adjacent sequences:  A270595 A270596 A270597 * A270599 A270600 A270601

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, Mar 20 2016

STATUS

approved

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Last modified January 29 04:57 EST 2020. Contains 331335 sequences. (Running on oeis4.)