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First differences of Mersenne numbers A001348, divided by 4.
5

%I #10 Oct 20 2023 16:55:23

%S 1,6,24,480,1536,30720,98304,1966080,132120576,402653184,33822867456,

%T 515396075520,1649267441664,32985348833280,2216615441596416,

%U 141863388262170624,432345564227567616,36317027395115679744,553402322211286548480,1770887431076116955136,148754544210393824231424

%N First differences of Mersenne numbers A001348, divided by 4.

%H Paolo Xausa, <a href="/A139240/b139240.txt">Table of n, a(n) for n = 1..450</a>

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

%t Differences[2^Prime[Range[25]]-1]/4 (* _Paolo Xausa_, Oct 20 2023 *)

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

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

%K easy,nonn

%O 1,2

%A _Omar E. Pol_, Apr 19 2008

%E a(10)-a(21) from _Paolo Xausa_, Oct 20 2023