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 A280854 Number of n X 3 0..2 arrays with no element equal to more than one of its king-move neighbors and with new values introduced in order 0 sequentially upwards. 1
 4, 29, 46, 96, 256, 678, 1698, 4358, 11218, 28650, 73354, 188066, 481554, 1233194, 3159018, 8091050, 20722730, 53077762, 135947682, 348198514, 891836994, 2284251018, 5850611770, 14985083066, 38381073050, 98304843826, 251786685106 (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) = 2*a(n-1) + 4*a(n-3) - a(n-4) + 2*a(n-6) - 2*a(n-7) for n>9. Empirical g.f.: x*(4 + 21*x - 12*x^2 - 12*x^3 - 48*x^4 + 11*x^5 - 4*x^6 - 16*x^7 + 12*x^8) / (1 - 2*x - 4*x^3 + x^4 - 2*x^6 + 2*x^7). - Colin Barker, Feb 14 2019 EXAMPLE Some solutions for n=4: ..0..0..1. .0..1..1. .0..0..1. .0..1..0. .0..1..2. .0..1..0. .0..0..1 ..1..2..1. .0..2..2. .1..2..2. .2..2..1. .2..1..0. .2..1..2. .2..1..2 ..0..2..0. .1..1..0. .0..1..0. .1..0..0. .2..0..2. .2..0..2. .2..0..0 ..1..1..0. .0..2..2. .0..2..2. .1..2..2. .1..1..2. .1..1..0. .1..1..2 CROSSREFS Column 3 of A280859. Sequence in context: A278823 A042597 A255635 * A042379 A184301 A192025 Adjacent sequences: A280851 A280852 A280853 * A280855 A280856 A280857 KEYWORD nonn AUTHOR R. H. Hardin, Jan 09 2017 STATUS approved

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Last modified December 7 05:59 EST 2023. Contains 367630 sequences. (Running on oeis4.)