A115520 Number of ordered triples (i,j,k) in range [0..n] satisfying i == j mod 2 and j == k mod 3.

1, 2, 5, 12, 23, 36, 61, 88, 123, 170, 227, 288, 373, 462, 565, 688, 827, 972, 1153, 1340, 1547, 1782, 2039, 2304, 2617, 2938, 3285, 3668, 4079, 4500, 4981, 5472, 5995, 6562, 7163, 7776, 8461, 9158, 9893, 10680, 11507, 12348, 13273, 14212, 15195, 16238, 17327, 18432, 19633

Offset

0,2

Links

Table of n, a(n) for n=0..48.

Formula

a(n) = binomial(n+1,3) - linear (PORC) correction term which depends on n mod 6.

Crossrefs

Cf. A115523.

Sequence in context: A116711 A247658 A109653 * A116735 A096376 A357288

Adjacent sequences: A115517 A115518 A115519 * A115521 A115522 A115523

Keyword

nonn

Author

N. J. A. Sloane and Vinay Vaishampayan, Mar 09 2006

Status

approved