# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a127470 Showing 1-1 of 1 %I A127470 #6 Sep 08 2013 18:25:08 %S A127470 1,4,2,9,0,6,16,12,0,8,25,0,0,0,20,36,18,24,0,0,12,49,0,0,0,0,0,42,64, %T A127470 56,0,48,0,0,0,32,81,0,72,0,0,0,0,0,54,100,50,0,0,80,0,0,0,0,40,121,0, %U A127470 0,0,0,0,0,0,0,0,110,144,108,96,72,0,72,0,0,0,0,0,48 %N A127470 Triangle equal to the matrix product A127466 * A051731. %F A127470 T(n,1) = n^2. %F A127470 T(n,n) = n*phi(n) = A002618(n). %e A127470 First few rows of the triangle are: %e A127470 1; %e A127470 4, 2; %e A127470 9, 0, 6; %e A127470 16, 12, 0, 8; %e A127470 25, 0, 0, 0, 20; %e A127470 36, 18, 24, 0, 0, 12; %e A127470 49, 0, 0, 0, 0, 0, 42; %e A127470 64, 56, 0, 48, 0, 0, 0, 32; %e A127470 81, 0, 72, 0, 0, 0, 0, 0, 54; %e A127470 ... %p A127470 A127470 := proc(n,k) %p A127470 add( A127466(n,j)*A051731(j,k),j=k..n) ; %p A127470 end proc: # _R. J. Mathar_, Sep 08 2013 %Y A127470 Cf. A127466, A051731, A127469 (row sums), A061949. %K A127470 nonn,tabl %O A127470 1,2 %A A127470 _Gary W. Adamson_, Jan 15 2007 %E A127470 Terms corrected by _R. J. Mathar_, Sep 08 2013 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE