A247722 Number of length n+3 0..4 arrays with no disjoint pairs in any consecutive four terms having the same sum

440, 1592, 5796, 21152, 77236, 282384, 1032952, 3779018, 13825712, 50587924, 185112244, 677378582, 2478738332, 9070607046, 33193012732, 121467142552, 444499919836, 1626617553810, 5952507849748, 21782859518402, 79713149293808

Offset

1,1

Comments

Column 4 of A247726

Links

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

Formula

Empirical: a(n) = 3*a(n-1) -6*a(n-2) +20*a(n-3) +54*a(n-4) -66*a(n-5) +313*a(n-6) -619*a(n-7) -797*a(n-8) -493*a(n-9) -5172*a(n-10) +1690*a(n-11) -2554*a(n-12) -84*a(n-13) +563*a(n-14) +3103*a(n-15) +12407*a(n-16) +10585*a(n-17) +147780*a(n-18) -40884*a(n-19) +31860*a(n-20) -71368*a(n-21) -151570*a(n-22) +112176*a(n-23) +332750*a(n-24) +324290*a(n-25) -1170072*a(n-26) -16160*a(n-27) -274274*a(n-28) +949452*a(n-29) +1863096*a(n-30) -195890*a(n-31) -2817928*a(n-32) -3449516*a(n-33) +2141463*a(n-34) +2233863*a(n-35) +3747347*a(n-36) +474055*a(n-37) -4040991*a(n-38) -2274839*a(n-39) -660322*a(n-40) +2250384*a(n-41) +934278*a(n-42) +180486*a(n-43) -56268*a(n-44) -559872*a(n-45)

Example

Some solutions for n=5
..1....0....3....2....4....0....0....4....3....3....0....0....4....4....0....0
..1....0....0....1....1....2....0....2....4....3....3....2....1....3....4....0
..2....1....2....0....4....4....2....4....2....1....2....4....4....0....1....2
..1....0....4....0....0....3....4....4....4....3....0....0....4....2....0....0
..3....2....1....3....4....0....3....1....0....0....3....4....2....4....0....0
..3....4....1....4....1....4....0....4....1....1....0....3....1....0....2....1
..3....1....1....0....2....4....4....2....1....3....2....3....0....3....0....2
..2....0....4....2....4....2....2....1....3....0....3....3....2....3....1....4

Crossrefs

Sequence in context: A072604 A158319 A250879 * A234202 A061626 A187239

Adjacent sequences: A247719 A247720 A247721 * A247723 A247724 A247725

Keyword

nonn

Author

R. H. Hardin, Sep 23 2014

Status

approved