A139240 First differences of Mersenne numbers A001348, divided by 4.

1, 6, 24, 480, 1536, 30720, 98304, 1966080, 132120576, 402653184, 33822867456, 515396075520, 1649267441664, 32985348833280, 2216615441596416, 141863388262170624, 432345564227567616, 36317027395115679744, 553402322211286548480, 1770887431076116955136, 148754544210393824231424

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..450

Formula

a(n) = A139238(n)/4 = A139239(n)/2.

Mathematica

Differences[2^Prime[Range[25]]-1]/4 (* Paolo Xausa, Oct 20 2023 *)

Prog

(PARI) a(n)=my(p=prime(n)); (2^nextprime(p+1)-2^p)/4 \\ Charles R Greathouse IV, Jan 03 2013

Crossrefs

Cf. A001348, A139237, A139238, A139239, A139243.

Sequence in context: A152886 A128614 A285018 * A052524 A267032 A234635

Adjacent sequences: A139237 A139238 A139239 * A139241 A139242 A139243

Keyword

easy,nonn

Author

Omar E. Pol, Apr 19 2008

Extensions

a(10)-a(21) from Paolo Xausa, Oct 20 2023

Status

approved