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 A127527 #7 Aug 12 2015 21:17:28
%S A127527 1,1,2,2,0,2,2,2,0,3,4,0,0,0,2,2,4,2,0,0,4,6,0,0,0,0,0,2,4,4,0,3,0,0,
%T A127527 0,4,6,0,4,0,0,0,0,0,3,4,8,0,0,2,0,0,0,0,4
%N A127527 Triangle T(n,k)= tau(k)*phi(n/k) if k|n, else T(n,k)=0.
%C A127527 Tau is the number of divisors A000005, and phi the Euler totient A000010.
%F A127527 T(n,k) = A000005(k)*A054523(n,k).
%F A127527 T(n,1) = A000010(n).
%F A127527 T(n,n) = A000005(n).
%F A127527 Sum_{k=1..n} T(n,k) = A000203(n).
%e A127527 First few rows of the triangle are:
%e A127527 1;
%e A127527 1, 2;
%e A127527 2, 0, 2;
%e A127527 2, 2, 0, 3;
%e A127527 4, 0, 0, 0, 2;
%e A127527 2, 4, 2, 0, 0, 4;
%e A127527 6, 0, 0, 0, 0, 0, 2;
%e A127527 4, 4, 0, 3, 0, 0, 0, 4;
%e A127527 ...
%p A127527 A127527 := proc(n,k) if n mod k = 0 then numtheory[tau](k)*numtheory[phi](n/k) ; else 0; end if; end proc: # _R. J. Mathar_, Apr 11 2011
%Y A127527 Cf. A054523, A000005, A000010, A000203.
%K A127527 nonn,tabl,easy
%O A127527 1,3
%A A127527 _Gary W. Adamson_, Jan 17 2007
%E A127527 Definition clarified by _R. J. Mathar_, Apr 11 2011