A369388 a(n) is the constant term in expansion of Product_{k=1..n} (x^prime(k) + 1 + 1/x^prime(k))^2.

1, 3, 9, 45, 249, 1373, 9177, 62257, 453179, 3320531, 24087877, 183643865, 1394580343, 10794949627, 85730722969, 686171829489, 5487361175591, 43981108061647, 358362244544957, 2922625435214613, 24006575088945973, 199229783030494775, 1653790732247194785

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Mathematica

Table[Coefficient[Product[(x^Prime[k] + 1 + 1/x^Prime[k])^2, {k, 1, n}], x, 0], {n, 0, 22}]

Crossrefs

Cf. A047653, A156181, A350880, A350881.

Sequence in context: A337849 A328267 A038059 * A174318 A338575 A004990

Adjacent sequences: A369385 A369386 A369387 * A369389 A369390 A369391

Keyword

nonn

Author

Ilya Gutkovskiy, Jan 22 2024

Status

approved