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

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, 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, 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

Offset

1,2

Comments

Multiply the infinite lower triangular matrices A127093 and A126988.

Links

Table of n, a(n) for n=1..90.

Formula

T(n,m) = sum_{j=m..n} A127093(n,j)*A126988(j,m).

T(n,1) = A001157(n).

Example

First few rows of the triangle are:
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;
...

Maple

A127093 := proc(n, m) if n mod m = 0 then m; else 0 ; fi; end:
A126988 := proc(n, k) if n mod k = 0 then n/k; else 0; fi; end:
A127097 := proc(n, m) add( A127093(n, j)*A126988(j, m), j=m..n) ; end:
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

Crossrefs

Cf. A126988, A000203, A127098, A001187, A001001 (row sums), A127093.

Sequence in context: A367210 A375613 A127098 * A040024 A196385 A178714

Adjacent sequences: A127094 A127095 A127096 * A127098 A127099 A127100

Keyword

nonn,tabl

Author

Gary W. Adamson, Jan 05 2007

Extensions

A-numbers corrected by R. J. Mathar, Aug 18 2009

Status

approved