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 A176347 #9 Feb 03 2019 22:29:32 %S A176347 0,1,3,3,5,7,11,9,15,11,19,15,23,17,23,21,35,31,39,35,27,29,47,43,35, %T A176347 59,39,63,41,55,71,59,45,71,51,71,87,57,95,99,59,79,83,107,65,91,69, %U A176347 119,111,71,119,77,103,131,81,143,115,87,119,143,159,95,131,99,167,159,101 %N A176347 n-th semiprime minus sum of its prime factors. %F A176347 a(n) = A001358(n) - A068318(n). %p A176347 From _R. J. Mathar_, Apr 20 2010: (Start) %p A176347 isA001358 := proc(n) numtheory[bigomega](n) = 2 ; end proc: %p A176347 A001358 := proc(n) option remember ; if n = 1 then return 4 ; else for a from procname(n-1)+1 do if isA001358(a) then return a; end if; end do; end if; end proc: %p A176347 A084126 := proc(n) min(op(numtheory[factorset](A001358(n)))) ; end proc: %p A176347 A084127 := proc(n) max(op(numtheory[factorset](A001358(n)))) ; end proc: %p A176347 A068318 := proc(n) A084126(n)+A084127(n) ; end proc: %p A176347 A176347 := proc(n) A001358(n)-A068318(n) ; end proc: seq(A176347(n),n=1..80) ; (End) %K A176347 nonn %O A176347 1,3 %A A176347 _Juri-Stepan Gerasimov_, Apr 15 2010 %E A176347 Entries checked by _R. J. Mathar_, Apr 20 2010