A369608 - OEIS

A369608

Number of solutions to +- 2 +- 3 +- 5 +- 7 +- ... +- prime(2*n) = prime(2*n).

0, 2, 2, 6, 14, 39, 125, 399, 1310, 4356, 14970, 51715, 178832, 635778, 2290019, 8106059, 29234378, 105635076, 384409483, 1408730050, 5193316109, 19170300330, 71421970661, 263893092145, 984568438169, 3686368605467, 13838552783467, 52008816746450

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..28.

FORMULA

a(n) = [x^prime(2*n)] Product_{k=1..2*n} (x^prime(k) + 1/x^prime(k)).

MATHEMATICA

Table[Coefficient[Product[(x^Prime[k] + 1/x^Prime[k]), {k, 1, 2 n}], x, Prime[2 n]], {n, 1, 28}]

CROSSREFS

Cf. A000040, A022894, A063890, A113040, A350695, A369390.

Sequence in context: A278331 A097341 A142710 * A014431 A201687 A259810

Adjacent sequences: A369605 A369606 A369607 * A369609 A369610 A369611

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Jan 27 2024

STATUS

approved