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 A176885 #13 Feb 18 2019 04:10:59 %S A176885 1,3,9,2,32,21,51,122,111,282,237,560,489,1898,1794,6200,995,2017, %T A176885 13428,19154,4059,2166,8151,73212,16341,58208,89088,176186,32721, %U A176885 383766,65483,530072,1940958,131013,740022,262083,1592642,4781120,5634480,524221 %N A176885 Let p*q = A006881(n) be the n-th number that is the product of two distinct primes, with p = prime(i), q=prime(j); a(n) = p^j - q^i. %e A176885 For n=3, A006881(3) = 14 = 2*7, p=2, i=1, q=7, j=4; a(n) = 2^4-7^1 = 9. %p A176885 A176885 := proc(n) c := A006881(n) ; pm := A020639(c) ; pk := A006530(c) ; pm^ numtheory[pi](pk) -pk^numtheory[pi](pm) ; end proc: %p A176885 seq(A176885(n),n=1..80) ; # _R. J. Mathar_, May 01 2010 %Y A176885 Cf. A006881. %K A176885 nonn %O A176885 1,2 %A A176885 _Juri-Stepan Gerasimov_, Apr 28 2010 %E A176885 a(14) and a(15) corrected and sequence extended by _R. J. Mathar_, May 01 2010 %E A176885 Definition clarified by _N. J. A. Sloane_, Feb 16 2019