cp's OEIS Frontend

A330820 Numbers of the form (M_p^2-1)^2, where M_p is a Mersenne prime, A000668. Also the second element of the power-spectral basis of A330817.

%I A330820 #10 Jan 07 2020 22:54:16
%S A330820 64,2304,921600,260112384,4501400872550400,295138898048817561600,
%T A330820 75557287266261531623424
%N A330820 Numbers of the form (M_p^2-1)^2, where M_p is a Mersenne prime, A000668. Also the second element of the power-spectral basis of A330817.
%C A330820 The first element of the power-spectral basis of A330817 is A330819.
%F A330820 a(n) = (A000668(n)^2-1)^2.
%e A330820 If n=1, a(1)=(3^2-1)^2=64.
%p A330820 A330820:=[]:
%p A330820 for www to 1 do
%p A330820 for i from 1 to 31 do
%p A330820 #ithprime(31)=127
%p A330820   p:=ithprime(i);
%p A330820   q:=2^p-1;
%p A330820 if isprime(q) then x:=(q^2-1)^2; A330820:=[op(A330820),x] fi;
%p A330820 od;
%p A330820 od;
%p A330820 A330820;
%t A330820 Array[((2^MersennePrimeExponent[#] - 1)^2 - 1)^2 &, 10] (* _Amiram Eldar_, Jan 07 2020 *)
%Y A330820 Cf. A000043, A000668, A330817, A330818, A330819.
%K A330820 nonn
%O A330820 1,1
%A A330820 _Walter Kehowski_, Jan 06 2020