%I #18 Oct 20 2024 03:51:56
%S 2,3,5,7,13,17,19,31,61,127,521,2281,3217,4253,9941,19937,21701,23209,
%T 44497,110503,216091,859433,1257787,3021377,6972593,13466917,20996011,
%U 30402457,32582657,42643801,57885161
%N Base-2 logarithm of A136007(n)+1.
%C The first 10 terms coincide with A109799.
%F a(n) = A000523(A136007(n)+1). - _Michel Marcus_, Apr 14 2021
%t q[n_] := n == 2 || Module[{d = Divisors[(n+1)/2]}, AllTrue[Range[3, Length[d]], d[[#]] >= 2 * d[[#-1]] &]]; Select[MersennePrimeExponent[Range[48]], q] (* _Amiram Eldar_, Oct 20 2024 *)
%Y Intersection of A000043 and A136002.
%Y Cf. A000523, A109799, A136003, A136005, A136007.
%K nonn,hard,more,changed
%O 1,1
%A _Omar E. Pol_, Dec 16 2008, Dec 20 2008
%E a(12)-(a31) from _Amiram Eldar_, Oct 20 2024