Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Jul 11 2015 10:55:24
%S 18446744073709551616,1333735776850284124449081472843776,
%T 106387358923716524807713475752456393740167855629859291136,
%U 12089258196146291747061760000000000000000000000000000000000000000
%N (n-th 4-almost prime)^(n-th 4-almost prime).
%C 4-almost prime analog of A051674. A114850 is semiprime analog of A051674. a(5) = 56^56 has 94 digits.
%F a(n) = A014613(n)^A014613(n).
%e a(1) = A014613(1)^A014613(1) = 16^16 = 18446744073709551616 = 2^64.
%e a(2) = A014613(2)^A014613(2) = 24^24 = 1333735776850284124449081472843776 = 2^72 * 3^24.
%e a(3) = A014613(3)^A014613(3) = 36^36 = 2^72 * 3^72.
%Y Cf. A001358, A014613, A051674, A113877, A114850.
%K easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Feb 22 2006