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A281444 E.g.f. C(x) satisfies: C(x) = cosh( Integral C(x)^8 dx ). 1
1, 1, 33, 3393, 715329, 255419649, 138324673377, 105723078203457, 108400924932329601, 143589514674637260801, 238670525628280806487713, 486411018516606613409744193, 1192731112687557517714202303169, 3464267964203640308372312350830849, 11761665286319167564660531957187772897, 46153563625764407361666349419808431496257, 207288280492672493893642973836751374267592961 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..16.

FORMULA

C(x)^2 - S(x)^2 = 1 and C(x) = 1 + Integral C(x)^8*S(x) dx, where S(x) is described by A281439.

PROG

(PARI) {a(n) = my(S=x, C=1); for(i=0, n, S = intformal( C^9 +x*O(x^(2*n))); C = 1 + intformal( S*C^8 ) ); (2*n)!*polcoeff(C, 2*n)}

for(n=0, 30, print1(a(n), ", "))

CROSSREFS

Sequence in context: A136541 A263105 A284072 * A242019 A305140 A282374

Adjacent sequences:  A281441 A281442 A281443 * A281445 A281446 A281447

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jan 21 2017

STATUS

approved

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Last modified March 7 10:14 EST 2021. Contains 341869 sequences. (Running on oeis4.)