[go: up one dir, main page]

login
A270056
Number of nX6 0..4 arrays with some element plus some horizontally or vertically adjacent neighbor totalling four exactly once.
1
6400, 26891280, 64599504300, 130850370606120, 243724207420143600, 431802177781617762960, 739963061540157663852060, 1238271081977141318093293560, 2035565501104551915702385538340
OFFSET
1,1
COMMENTS
Column 6 of A270058.
LINKS
FORMULA
Empirical: a(n) = 3820*a(n-1) -5141812*a(n-2) +3101631176*a(n-3) -1053325179812*a(n-4) +225930415991302*a(n-5) -32465460013961126*a(n-6) +3207851298752368554*a(n-7) -217580289808005247320*a(n-8) +9706372592807726300356*a(n-9) -240860672010312397879341*a(n-10) +115473715969373609881354*a(n-11) +212020581493432030950883197*a(n-12) -6862246606169040312770752410*a(n-13) +69977373438286287807082579927*a(n-14) +1240079187008116763603015457992*a(n-15) -46282001268519984080947125145024*a(n-16) +500401562102338128223713704959392*a(n-17) +318529972429762141211745078727216*a(n-18) -59633160184685032320235324860614016*a(n-19) +541188478996193175160548803121462848*a(n-20) -795703540248872440476678397698018432*a(n-21) -18690496956959404408797298248907914816*a(n-22) +150522035368938828426070273182800557568*a(n-23) -511422590153363523124456598370318521344*a(n-24) +826346567199579029883524578636954353664*a(n-25) -514087593143152142368253004618643603456*a(n-26) for n>27
EXAMPLE
Some solutions for n=1
..4..2..4..0..0..3. .2..3..2..1..3..3. .4..1..2..2..0..0. .1..2..0..4..2..3
CROSSREFS
Cf. A270058.
Sequence in context: A251454 A237954 A269827 * A031578 A252612 A259060
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 09 2016
STATUS
approved