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Index of Mersenne number A000225 that is also Mersenne prime A000668, minus n-th prime: a(n) = A000043(n) - A000040(n).
4

%I #12 Oct 21 2024 04:36:12

%S 0,0,0,0,2,4,2,12,38,60,76,90,480,564,1232,2150,2222,3156,4186,4352,

%T 9616,9862,11130,19848,21604,23108,44394,86136,110394,131936,215964,

%U 756708,859296,1257648,1398120,2976070,3021220,6972430,13466750,20995838,24036404,25964770

%N Index of Mersenne number A000225 that is also Mersenne prime A000668, minus n-th prime: a(n) = A000043(n) - A000040(n).

%H Amiram Eldar, <a href="/A153801/b153801.txt">Table of n, a(n) for n = 1..48</a>

%t With[{max = 48}, MersennePrimeExponent[Range[max]] - Prime[Range[max]]] (* _Amiram Eldar_, Oct 21 2024 *)

%Y Cf. A000040, A000043, A000668, A000225, A000396, A007691, A153800, A153802, A153803.

%K nonn,changed

%O 1,5

%A _Omar E. Pol_, Jan 13 2009

%E More terms from _R. J. Mathar_, Feb 19 2009

%E More terms from _Jinyuan Wang_, Mar 02 2020