cp's OEIS Frontend

A127098 Triangle T(n,m) read by rows: product A127093 * A127094.

%I A127098 #7 Aug 12 2015 21:19:32
%S A127098 1,5,2,10,0,3,21,2,8,4,26,0,0,0,5,50,2,3,18,12,6,50,0,0,0,0,0,7,85,2,
%T A127098 8,4,32,0,16,8,91,0,3,0,0,0,27,0,9,130,2,0,0,5,50,0,0,20,10,122,0,0,0,
%U A127098 0,0,0,0,0,0,11,210,2,11,22,12,6,72,0,48,36,24,12,170,0,0,0,0,0,0,0,0,0,0,0,13,250,2,0,0,0,0,7,98,0
%N A127098 Triangle T(n,m) read by rows: product A127093 * A127094.
%C A127098 A127097 is a close companion.
%F A127098 T(n,m) = Sum_{k=m..n} A127093(n,k)*A127094(k,m).
%F A127098 Row sums: Sum_{m=1..n} T(n,m) = A001001(n).
%F A127098 Left column: T(1,m) = A001157(m).
%e A127098 First few rows of the triangle are:
%e A127098 1;
%e A127098 5, 2;
%e A127098 10, 0, 3;
%e A127098 21, 2, 8, 4;
%e A127098 26, 0, 0, 0, 5;
%e A127098 50, 2, 3, 18, 12, 6;
%e A127098 50, 0, 0, 0, 0, 0, 7;
%e A127098 85, 2, 8, 4, 32, 0, 16, 8;
%p A127098 A127093 := proc(n,m) if m> n or m<1 or n < 1 then 0 ; elif (n mod m) = 0 then m; else 0 ; fi; end:
%p A127098 A127094 := proc(n,m) A127093(n,n-m+1) ; end: A127098 := proc(n,m) add( A127093(n,k)*A127094(k,m),k=1..n) ; end:
%p A127098 for n from 1 to 30 do for m from 1 to n do printf("%d,",A127098(n,m)) ; od: od: # _R. J. Mathar_, Mar 02 2009
%Y A127098 Cf. A127097, A127093, A127094, A001001, A001157.
%K A127098 nonn,tabl,easy
%O A127098 1,2
%A A127098 _Gary W. Adamson_, Jan 05 2007
%E A127098 Edited and extended by _R. J. Mathar_, Mar 02 2009