A139300 a(n) = 2^(2p - 1)/8, where p is the n-th Mersenne prime A000668(n).

4, 1024, 288230376151711744, 1809251394333065553493296640760748560207343510400633813116524750123642650624

Offset

1,1

Links

Table of n, a(n) for n=1..4.

Formula

a(n) = 2^(2*A000668(n)-1)/8 = A139294(n)/8.

Mathematica

a[n_] := 2^(2^(MersennePrimeExponent[n] + 1) - 6); Array[a, 4] (* Amiram Eldar, Jul 10 2025 *)

Crossrefs

Cf. A000668, A139294, A139295, A139296, A139297, A139298, A139299, A139301, A139302, A139303, A139304, A139305, A139306.

Sequence in context: A368371 A217024 A013780 * A004804 A221228 A159859

Adjacent sequences: A139297 A139298 A139299 * A139301 A139302 A139303

Keyword

nonn

Author

Omar E. Pol, Apr 13 2008

Extensions

a(4) from Amiram Eldar, Jul 10 2025

Status

approved