A262451 Number of (n+3)X(2+3) 0..1 arrays with each row and column divisible by 15, read as a binary number with top and left being the most significant bits.

3, 5, 9, 17, 51, 117, 281, 705, 2115, 6597, 20105, 60433, 181299, 555125, 1688153, 5101505, 15304515, 46132805, 138926985, 417770513, 1253311539, 3762126453, 11293365145, 33895137473, 101685412419, 305043012293, 915147434121

Offset

1,1

Comments

Column 2 of A262457.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -a(n-2) -8*a(n-3) +48*a(n-4) -168*a(n-5) +48*a(n-6) +312*a(n-7) -955*a(n-8) +2884*a(n-9) -955*a(n-10) -4832*a(n-11) +7632*a(n-12) -16032*a(n-13) +7632*a(n-14) +17568*a(n-15) +4886*a(n-16) -72248*a(n-17) +4886*a(n-18) +197200*a(n-19) -366336*a(n-20) +873744*a(n-21) -366336*a(n-22) -1155888*a(n-23) +1014058*a(n-24) -588568*a(n-25) +1014058*a(n-26) -2290528*a(n-27) +6020160*a(n-28) -17209056*a(n-29) +6020160*a(n-30) +27546528*a(n-31) -27604133*a(n-32) +27776948*a(n-33) -27604133*a(n-34) +27085688*a(n-35) -75797424*a(n-36) +221932632*a(n-37) -75797424*a(n-38) -362608200*a(n-39) +362785825*a(n-40) -363318700*a(n-41) +362785825*a(n-42) -361187200*a(n-43) +406335600*a(n-44) -541780800*a(n-45) +406335600*a(n-46)

Example

Some solutions for n=4
..0..0..0..0..0....0..1..1..1..1....1..1..1..1..0....1..1..1..1..0
..0..0..0..0..0....0..1..1..1..1....0..0..0..0..0....0..0..0..0..0
..0..0..0..0..0....0..1..1..1..1....0..0..0..0..0....1..1..1..1..0
..0..1..1..1..1....0..1..1..1..1....1..1..1..1..0....1..1..1..1..0
..0..1..1..1..1....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..1..1..1..1....0..0..0..0..0....1..1..1..1..0....1..1..1..1..0
..0..1..1..1..1....0..0..0..0..0....1..1..1..1..0....0..0..0..0..0

Crossrefs

Cf. A262457.

Sequence in context: A006723 A217097 A298590 * A096390 A092264 A135729

Adjacent sequences: A262448 A262449 A262450 * A262452 A262453 A262454

Keyword

nonn

Author

R. H. Hardin, Sep 23 2015

Status

approved