A039671 Row sums up to the main diagonal of the "postage stamp" array (n,m >= 0) defined in A007059.

1, 1, 3, 8, 21, 53, 130, 310, 724, 1661, 3757, 8398, 18588, 40800, 88918, 192592, 414907, 889631, 1899554, 4040864, 8567342, 18109698, 38176280, 80278798, 168432854, 352658013, 736977583, 1537420460, 3202035086, 6658948608

Offset

0,3

Links

Table of n, a(n) for n=0..29.

Formula

Conjecture: a(n) = Sum_{k=1..n} A126198(n,k), for n > 0. - L. Edson Jeffery, Nov 29 2013

Example

a(0)=1, a(1)=0+1=1, a(2)=0+1+2=3, a(3)=0+1+3+4=8.

Mathematica

f[ n_, m_ ] := f[ n, m ]=Which[ n>0, Sum[ f[ n-i, m ], {i, 1, m} ], n<0, 0, n==0, 1 ] Table[ Sum[ f[ n, j ], {j, 0, n} ], {n, 0, 30} ]

Crossrefs

Cf. A007059.

Sequence in context: A152086 A014396 A170881 * A267946 A166287 A186812

Adjacent sequences: A039668 A039669 A039670 * A039672 A039673 A039674

Keyword

easy,nonn

Author

Richard L. Ollerton and Eirwyn L. Ollerton

Status

approved