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A207101 Number of 0..n arrays x(0..3) of 4 elements with each no smaller than the sum of its two previous neighbors modulo (n+1). 1

%I

%S 8,26,68,140,274,462,760,1158,1720,2431,3392,4550,6048,7825,10032,

%T 12597,15726,19285,23540,28343,33968,40250,47536,55575,64792,74916,

%U 86380,98890,112970,128216,145248,163636,184008,205905,230064,255892,284240,314483

%N Number of 0..n arrays x(0..3) of 4 elements with each no smaller than the sum of its two previous neighbors modulo (n+1).

%C Row 4 of A207100.

%H R. H. Hardin, <a href="/A207101/b207101.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-2) + 2*a(n-3) - 3*a(n-4) - 6*a(n-5) + 6*a(n-7) + 3*a(n-8) - 2*a(n-9) - 3*a(n-10) + a(n-12).

%F Empirical g.f.: x*(8 + 26*x + 44*x^2 + 46*x^3 + 42*x^4 + 32*x^5 + 18*x^6 + 4*x^7 - 2*x^8 - 3*x^9 + x^11) / ((1 - x)^5*(1 + x)^3*(1 + x + x^2)^2). - _Colin Barker_, Jun 19 2018

%e Some solutions for n=5:

%e ..2....3....1....1....3....3....3....1....3....3....4....3....0....4....0....0

%e ..4....3....1....5....3....4....3....1....3....3....5....3....0....4....2....0

%e ..2....4....4....4....3....3....3....5....4....4....3....3....2....2....4....4

%e ..3....1....5....5....1....2....0....4....2....4....5....2....3....3....2....4

%Y Cf. A207100.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 15 2012

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Last modified February 4 04:05 EST 2023. Contains 360045 sequences. (Running on oeis4.)