A262846 Number of (n+2)X(4+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.

318, 3181, 37635, 420654, 3896365, 39348387, 417279054, 3999504445, 39913429587, 409857534030, 4017392736541, 40104536998707, 405732145282158, 4021339824862381, 40178930760566115, 403823141865184494

Offset

1,1

Comments

Column 4 of A262849.

Links

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

Formula

Empirical: a(n) = 13*a(n-1) -30*a(n-2) +775*a(n-3) -10075*a(n-4) +23250*a(n-5) -187265*a(n-6) +2434445*a(n-7) -5617950*a(n-8) +18375455*a(n-9) -238880915*a(n-10) +551263650*a(n-11) -585288123*a(n-12) +7608745599*a(n-13) -17558643690*a(n-14) -12851058675*a(n-15) +167063762775*a(n-16) -385531760250*a(n-17) +757921180765*a(n-18) -9852975349945*a(n-19) +22737635422950*a(n-20) -1115961555955*a(n-21) +14507500227415*a(n-22) -33478846678650*a(n-23) -69403913471776*a(n-24) +902250875133088*a(n-25) -2082117404153280*a(n-26) -67517783528000*a(n-27) +877731185864000*a(n-28) -2025533505840000*a(n-29)

Example

Some solutions for n=3
..0..1..1..1..0..0....1..1..1..0..0..0....1..0..0..0..1..1....0..0..0..0..0..0
..1..0..0..0..1..1....0..0..0..1..1..1....1..0..1..0..1..0....1..0..0..0..1..1
..1..1..1..1..1..1....0..0..0..0..0..0....1..1..0..0..0..1....0..1..1..1..0..0
..0..1..0..1..0..1....0..0..1..1..1..0....1..0..0..0..1..1....0..1..0..1..0..1
..1..1..0..0..0..1....0..0..0..0..0..0....0..1..1..1..0..0....1..0..1..0..1..0

Crossrefs

Cf. A262849.

Sequence in context: A075153 A204835 A281078 * A225579 A261281 A126838

Adjacent sequences: A262843 A262844 A262845 * A262847 A262848 A262849

Keyword

nonn

Author

R. H. Hardin, Oct 03 2015

Status

approved