A181426 - OEIS

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A181426

Numerator of Sum_{k=1..n} k^4 / Product_{k=1..n} k^4.

1, 17, 49, 59, 979, 91, 167, 731, 5111, 517, 1817, 6071, 109, 18241, 22289, 2771, 131, 28823, 67, 51619, 11911, 34891, 15557, 257, 1949, 22313, 2267, 14123, 153931, 5273999, 1, 3167, 45091, 3569, 268309, 126947, 4217, 127, 369641, 201679, 85739

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

OFFSET

1,2

COMMENTS

a(n) = 1 for n = {1, 31, 59, 94, 104, 122, 133, 181, 206, 223, ...} = A166604.

LINKS

Table of n, a(n) for n=1..41.

EXAMPLE

The first few fractions are 1, 17/16, 49/648, 59/55296, 979/207360000, 91/10749542400, 167/23044331520000, ... = A181426/A334734.

MATHEMATICA

Table[Numerator[Sum[ k^4, {k, 1, n}] / Product[k^4, {k, 1, n}]], {n, 1, 100}]

PROG

(PARI) a(n) = numerator(sum(k=1, n, k^4)/prod(k=1, n, k^4)); \\ Michel Marcus, May 09 2020

CROSSREFS

Cf. A090585 = Numerator of Sum/Product of first n numbers.

Cf. A125294 = Numerator of Sum/Product of squares of first n numbers.

Cf. A166604, A334734 (denominators).

Sequence in context: A297988 A210372 A239130 * A029487 A069129 A176273

Adjacent sequences: A181423 A181424 A181425 * A181427 A181428 A181429

KEYWORD

nonn,frac

AUTHOR

Alexander Adamchuk, Oct 18 2010

STATUS

approved