A354655 - OEIS

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A354655

Column 2 of triangle A354650: a(n) = A354650(n,2), for n >= 1.

3, 27, 147, 630, 2295, 7476, 22302, 62100, 163260, 409080, 983367, 2280306, 5122026, 11184075, 23806575, 49521456, 100872135, 201558231, 395675475, 764130780, 1453424259, 2725614243, 5044092372, 9219499800, 16655554125, 29759775435, 52623867051

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Paul D. Hanna, Table of n, a(n) for n = 1..100

FORMULA

a(n) = (-1)^(n+1) * A354649(n,2), for n >= 1.

a(n) = A354650(n,2), for n >= 1.

PROG

(PARI) {A354650(n, k) = my(A=[1+y]); for(i=1, n, A = concat(A, 0);

A[#A] = polcoeff(y + sum(m=0, sqrtint(2*#A+9), (-1)^m * x^(m*(m-1)/2) * (1 - x^(2*m+1)) * Ser(A)^(m*(m+1)/2) ), #A-1) );

polcoeff(A[n+1], k, y)}

for(n=1, 30, print1(A354650(n, 2), ", "))

CROSSREFS

Cf. A354649, A354650, A354656.

Sequence in context: A001796 A174613 A341566 * A127509 A108142 A056263

Adjacent sequences: A354652 A354653 A354654 * A354656 A354657 A354658

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jun 02 2022

STATUS

approved