A270147 Number of nX4 0..7 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling seven exactly once.

1176, 4126368, 5750902944, 6697695002208, 7142783643783792, 7232246139319438944, 7076007579749239522560, 6756572506861579320074976, 6335222052939240175011338736, 5856894219696861529450357235808

Offset

1,1

Comments

Column 4 of A270150.

Links

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

Formula

Empirical: a(n) = 1742*a(n-1) -827249*a(n-2) +55735166*a(n-3) +2410177430*a(n-4) -208388398056*a(n-5) -3167015848153*a(n-6) +256479806611406*a(n-7) +2376722394136390*a(n-8) -119974226647646126*a(n-9) -748066037036869804*a(n-10) +14495677890626797680*a(n-11) -44282335922464026472*a(n-12) -87656882172897101898*a(n-13) +633122185223835748191*a(n-14) -486595208994066512314*a(n-15) -2521515704709696475982*a(n-16) +4786585967458397581320*a(n-17) +2256779180091586437315*a(n-18) -11568026205666473386010*a(n-19) +4081366110373471964624*a(n-20) +11206797106037834726810*a(n-21) -8694022358907130403200*a(n-22) -3768022188795704598344*a(n-23) +5316074296028246592431*a(n-24) -410670862474703529840*a(n-25) -1029555514715631146860*a(n-26) +336961514541159804000*a(n-27) -22395037969800912100*a(n-28) -1605006621279476000*a(n-29) -20684134872040000*a(n-30) for n>31

Example

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

Crossrefs

Cf. A270150.

Sequence in context: A233870 A237774 A223340 * A270114 A258912 A237094

Adjacent sequences: A270144 A270145 A270146 * A270148 A270149 A270150

Keyword

nonn

Author

R. H. Hardin, Mar 12 2016

Status

approved