A052116 Number of nonnegative integer pairs (i,j) with binomial(i+r,r) + binomial(j+r,r) <= binomial(n+r,r), r=3.

0, 1, 4, 9, 15, 24, 33, 46, 58, 73, 92, 109, 132, 152, 179, 202, 231, 262, 290, 325, 358, 397, 434, 476, 517, 558, 607, 650, 702, 753, 804, 859, 915, 974, 1033, 1092, 1157, 1221, 1286, 1359, 1426, 1499, 1571, 1650, 1727, 1802, 1883, 1967, 2054, 2135, 2228

Offset

0,3

Links

Robert Israel, Table of n, a(n) for n = 0..10000

Maple

N:= 100: # for a(0) .. a(N)
L:= [seq(binomial(n+3, 3), n=0..N)]:
f:= proc(n) local i, j, v, t;
   t:= 0;
   for i from 0 to n-1 while 2*L[i+1] <= L[n+1] do
     j:= ListTools:-BinaryPlace(L, L[n+1]-L[i+1]+1);
     t:= t + 2*(j-i)-1;
   od;
t
end proc:
map(f, [$0..N]); # Robert Israel, Dec 10 2024

Crossrefs

Cf. A052115, A052117, A052118.

Sequence in context: A004629 A348338 A065893 * A109641 A134675 A050530

Adjacent sequences: A052113 A052114 A052115 * A052117 A052118 A052119

Keyword

nonn

Author

Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Jan 21 2000

Status

approved