A254829 Number of length 2 1..(n+1) arrays with every leading partial sum divisible by 2, 3 or 5.

2, 6, 10, 16, 23, 26, 35, 44, 55, 60, 75, 81, 98, 115, 135, 143, 168, 177, 204, 229, 257, 268, 301, 329, 362, 392, 427, 441, 484, 498, 539, 579, 622, 664, 713, 730, 778, 823, 874, 893, 950, 970, 1026, 1079, 1138, 1160, 1227, 1250, 1317, 1378, 1445, 1470, 1545, 1609

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) + 2*a(n-30) - 2*a(n-31) - a(n-60) + a(n-61).

Example

All solutions for n=4:
..2....2....5....5....4....5....2....4....3....3....4....3....3....4....5....2
..4....2....4....3....5....5....1....4....2....3....2....5....1....1....1....3

Crossrefs

Row 2 of A254827.

Sequence in context: A294013 A183575 A096184 * A030511 A351635 A071597

Adjacent sequences: A254826 A254827 A254828 * A254830 A254831 A254832

Keyword

nonn

Author

R. H. Hardin, Feb 08 2015

Status

approved