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A234668 Number of (n+1) X (2+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings). 1
3816, 28860, 217968, 1648188, 12470688, 94430072, 715532392, 5425977036, 41174389648, 312684001244, 2376211767256, 18071478927288, 137531947836880, 1047471793293388, 7983305435427952, 60890806801849980, 464753484540401824 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 35*a(n-1) -234*a(n-2) -5393*a(n-3) +83088*a(n-4) +72599*a(n-5) -7727281*a(n-6) +30601466*a(n-7) +288437560*a(n-8) -2223662740*a(n-9) -2827663592*a(n-10) +61030210280*a(n-11) -68134000167*a(n-12) -723492961431*a(n-13) +1379135043174*a(n-14) +4956504550981*a(n-15) -10336340466744*a(n-16) -22249573436775*a(n-17) +42072453243081*a(n-18) +68185197096618*a(n-19) -103181037099516*a(n-20) -142550751258288*a(n-21) +157651414286112*a(n-22) +199205608411008*a(n-23) -149554834911360*a(n-24) -179827747799040*a(n-25) +84774205497600*a(n-26) +99173800742400*a(n-27) -26026116480000*a(n-28) -29990476800000*a(n-29) +3292047360000*a(n-30) +3762339840000*a(n-31).

EXAMPLE

Some solutions for n=2:

  5 2 4   2 1 0   6 5 1   4 2 1   5 1 2   4 0 7   6 3 4

  7 0 6   0 3 6   7 2 2   0 2 5   5 5 2   4 4 7   1 2 7

  3 0 2   0 7 6   2 1 5   1 7 6   6 2 3   3 7 6   6 3 4

CROSSREFS

Column 2 of A234672.

Sequence in context: A228545 A179174 A232083 * A259522 A209894 A255621

Adjacent sequences:  A234665 A234666 A234667 * A234669 A234670 A234671

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 29 2013

STATUS

approved

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Last modified September 29 22:48 EDT 2022. Contains 357092 sequences. (Running on oeis4.)