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A250629
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Number of (n+1)X(5+1) 0..2 arrays with nondecreasing x(i,j)+x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction
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1
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7924, 49310, 241742, 1014946, 3719562, 12291286, 37072806, 103697021, 271291108, 669808747, 1569996305, 3513623873, 7540411459, 15579673489, 31093283813, 60120915521, 112914033620, 206467172321, 368317607017, 642203244548
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 8*a(n-1) -21*a(n-2) +105*a(n-4) -168*a(n-5) -91*a(n-6) +512*a(n-7) -330*a(n-8) -560*a(n-9) +910*a(n-10) -910*a(n-12) +560*a(n-13) +330*a(n-14) -512*a(n-15) +91*a(n-16) +168*a(n-17) -105*a(n-18) +21*a(n-20) -8*a(n-21) +a(n-22) for n>29
Empirical for n mod 2 = 0: a(n) = (421/43589145600)*n^14 + (1907/2075673600)*n^13 + (3559/95800320)*n^12 + (1649/1995840)*n^11 + (66037/5806080)*n^10 + (57283/460800)*n^9 + (80070653/60963840)*n^8 + (3540311/362880)*n^7 + (1859660507/43545600)*n^6 + (1321110737/7257600)*n^5 + (3512186257/2661120)*n^4 - (440960999/190080)*n^3 + (188443760621/16816800)*n^2 + (71176067/12012)*n - 36235 for n>7
Empirical for n mod 2 = 1: a(n) = (421/43589145600)*n^14 + (1907/2075673600)*n^13 + (3559/95800320)*n^12 + (1649/1995840)*n^11 + (66037/5806080)*n^10 + (57283/460800)*n^9 + (80070653/60963840)*n^8 + (3540311/362880)*n^7 + (1858571867/43545600)*n^6 + (1323696257/7257600)*n^5 + (6988048919/5322240)*n^4 - (877698163/380160)*n^3 + (11813884014349/1076275200)*n^2 + (67190231047/10250240)*n - (19068997/512) for n>7
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EXAMPLE
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Some solutions for n=2
..0..0..0..0..0..2....1..0..0..2..1..2....0..0..1..1..2..2....0..0..0..0..2..2
..0..0..1..0..2..2....0..1..1..1..2..2....0..0..1..2..2..2....0..1..0..0..2..2
..0..1..0..1..2..2....2..1..1..2..2..2....1..0..1..2..2..2....1..0..2..2..2..2
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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