cp's OEIS Frontend

A127097 Triangle T(n,m) = A127093 * A126988 read by rows.

%I A127097 #7 Aug 12 2015 21:12:06
%S A127097 1,5,2,10,0,3,21,10,0,4,26,0,0,0,5,50,20,15,0,0,6,50,0,0,0,0,0,7,85,
%T A127097 42,0,20,0,0,0,8,91,0,30,0,0,0,0,0,9,130,52,0,0,25,0,0,0,0,10,122,0,0,
%U A127097 0,0,0,0,0,0,0,11,210,100,63,40,0,30,0,0,0,0,0,12,170,0,0,0,0,0,0,0,0,0,0,0
%N A127097 Triangle T(n,m) = A127093 * A126988 read by rows.
%C A127097 Multiply the infinite lower triangular matrices A127093 and A126988.
%F A127097 T(n,m) = sum_{j=m..n} A127093(n,j)*A126988(j,m).
%F A127097 T(n,1) = A001157(n).
%e A127097 First few rows of the triangle are:
%e A127097 1;
%e A127097 5, 2;
%e A127097 10, 0, 3;
%e A127097 21, 10, 0, 4;
%e A127097 26, 0, 0, 0, 5;
%e A127097 50, 20, 15, 0, 0, 6;
%e A127097 50, 0, 0, 0, 0, 0, 7;
%e A127097 ...
%p A127097 A127093 := proc(n,m) if n mod m = 0 then m; else 0 ; fi; end:
%p A127097 A126988 := proc(n,k) if n mod k = 0 then n/k; else 0; fi; end:
%p A127097 A127097 := proc(n,m) add( A127093(n,j)*A126988(j,m),j=m..n) ; end:
%p A127097 for n from 1 to 15 do for m from 1 to n do printf("%d,",A127097(n,m)) ; od: od: # _R. J. Mathar_, Aug 18 2009
%Y A127097 Cf. A126988, A000203, A127098, A001187, A001001 (row sums), A127093.
%K A127097 nonn,tabl
%O A127097 1,2
%A A127097 _Gary W. Adamson_, Jan 05 2007
%E A127097 A-numbers corrected by _R. J. Mathar_, Aug 18 2009