A234699 Number of (n+1) X (3+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant-stress 1 X 1 tilings).

16848, 74308, 329984, 1558600, 7424496, 37338544, 189345872, 1006857472, 5389971408, 30077051488, 168561386384, 979772704480, 5704468149456, 34304416485664, 206090647457552, 1274575646527072, 7855291807049808

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n = 1..186

Formula

Empirical: a(n) = 20*a(n-1) +141*a(n-2) -5340*a(n-3) +5451*a(n-4) +616740*a(n-5) -2678805*a(n-6) -39706740*a(n-7) +278440182*a(n-8) +1491646680*a(n-9) -16092380232*a(n-10) -27470360160*a(n-11) +601403119168*a(n-12) -194332088960*a(n-13) -15257818574160*a(n-14) +26729605928640*a(n-15) +263906583339744*a(n-16) -801813357648000*a(n-17) -2982678610973184*a(n-18) +13948745101747200*a(n-19) +18588639920403456*a(n-20) -156794289434542080*a(n-21) -1681574850293760*a(n-22) +1140373919202508800*a(n-23) -1022866437252096000*a(n-24) -5015897891205120000*a(n-25) +8536532135362560000*a(n-26) +10656426280550400000*a(n-27) -31534442652303360000*a(n-28) +815374290124800000*a(n-29) +46191901645209600000*a(n-30) -31856483893248000000*a(n-31).

Example

Some solutions for n=2:
  7 1 6 5     5 5 5 0     6 5 6 5     6 0 3 2     5 0 3 3
  2 1 1 5     7 2 7 7     2 6 2 6     5 4 2 6     7 7 5 0
  3 7 2 1     1 1 1 6     3 2 3 2     7 1 4 3     6 1 4 4

Crossrefs

Column 3 of A234702.

Sequence in context: A061364 A203891 A088164 * A204639 A233986 A170797

Adjacent sequences: A234696 A234697 A234698 * A234700 A234701 A234702

Keyword

nonn

Author

R. H. Hardin, Dec 29 2013

Status

approved