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 A127641 #7 Aug 18 2015 00:10:09
%S A127641 2,3,3,5,0,5,7,7,0,7,11,0,0,0,11,13,13,13,0,0,13,17,0,0,0,0,0,17,19,
%T A127641 19,0,19,0,0,0,19,23,0,23,0,0,0,0,0,23,29,29,0,0,29,0,0,0,0,29,31,0,0,
%U A127641 0,0,0,0,0,0,0,31,37,37,37,37,0,37,0,0,0,0,0,37,41,0,0,0,0,0,0,0,0,0,0,0,41
%N A127641 A127640 * A051731 as infinite lower triangular matrices.
%C A127641 A prime transform of A051731.
%e A127641 First few rows of the triangle are:
%e A127641 2;
%e A127641 3, 3;
%e A127641 5, 0, 5;
%e A127641 7, 7, 0, 7;
%e A127641 11, 0, 0, 0, 11;
%e A127641 13, 13, 13, 0, 0, 13;
%e A127641 ...
%p A127641 A127640 := proc(n,m) if m < n then 0; else ithprime(n) ; fi ; end: A051731 := proc(n,k) if n mod k = 0 then 1 ; else 0 ; fi ; end: A127641 := proc(n,m) add( A127640(n,k)*A051731(k,m),k=1..n) ; end: for n from 1 to 15 do for m from 1 to n do printf("%d,",A127641(n,m)) ; od ; od ; # _R. J. Mathar_, May 19 2007
%Y A127641 Cf. A127640, A051731, A127638, A127639.
%K A127641 nonn,tabl,easy
%O A127641 1,1
%A A127641 _Gary W. Adamson_, Jan 21 2007
%E A127641 More terms from _R. J. Mathar_, May 19 2007