This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A215776 #25 Mar 02 2016 17:13:33
%S A215776 1,2,3,2,3,2,3,3,3,2,3,5,2,3,3,3,3,2,5,5,2,3,3,2,3,7,3,3,3,5,5,5,3,2,
%T A215776 3,2,5,5,3,3,3,7,2,3,3,3,7,5,2,5,5,5,3,2,3,5,3,7,3,5,2,5,5,3,3,2,3,7,
%U A215776 3,3,3,3,5,7,2,5,7,11,2,7,3,5,5,5,3,3,3
%N A215776 Second-largest prime factor of the n-th number that is a product of exactly n primes.
%C A215776 This is to A215405 as 2nd largest prime factor is to largest (greatest) prime factor. Technically, the prime numbers are "1-almost prime."
%F A215776 a(n) = A087039(A101695(n)).
%e A215776 a(2) = 2 because the 2nd number that is a product of exactly 2 primes
%e A215776 (semiprime) is 6 = 2*3, so 2 is the 2nd largest of those two prime factors.
%e A215776 a(4) = 2 because the 4th number that is a product of exactly 4 primes is 40 = 2*2*2*5, so 2 is the 2nd largest of those two distinct prime factors {2,5}. This requires clarity in "distinct prime factors" versus merely "prime factors."
%e A215776 a(87) = 3 because the 87th number that is a product of 87 primes is 5048474222710691433572990976 = 2^84 3^2 29, and 3 is the 2nd largest prime factor.
%p A215776 A215776 := proc(n)
%p A215776 A087039(A101695(n)) ;
%p A215776 end proc: # _R. J. Mathar_, Sep 14 2012
%Y A215776 Cf. A087039, A101695, A215405.
%K A215776 nonn
%O A215776 1,2
%A A215776 _Jonathan Vos Post_, Aug 23 2012
%E A215776 Corrected by _R. J. Mathar_, Sep 14 2012
%E A215776 More terms from _Lars Blomberg_, Mar 02 2016