A139298 a(n) = 2^(2p - 1)/4, where p is the n-th Mersenne prime A000668(n).

8, 2048, 576460752303423488, 3618502788666131106986593281521497120414687020801267626233049500247285301248

Offset

1,1

Links

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

Formula

a(n) = 2^(2*A000668(n) - 1)/4 = A139294(n)/4.

Mathematica

a[n_] := 2^(2^(MersennePrimeExponent[n] + 1) - 5); Array[a, 4] (* Amiram Eldar, Jul 10 2025 *)

Crossrefs

Cf. A000668, A139294, A139295, A139296, A139297, A139299, A139300, A139301, A139302, A139303, A139304, A139305, A139306.

Sequence in context: A299306 A299464 A300107 * A004819 A001375 A281651

Adjacent sequences: A139295 A139296 A139297 * A139299 A139300 A139301

Keyword

nonn

Author

Omar E. Pol, Apr 13 2008

Status

approved