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A302429
Number of 4Xn 0..1 arrays with every element equal to 0, 1, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
8, 10, 21, 42, 83, 235, 532, 1250, 2839, 6972, 16274, 38248, 89001, 212049, 499017, 1173745, 2751350, 6500703, 15315258, 36048935, 84729145, 199692020, 470383120, 1107496019, 2605813342, 6136943366, 14452575010, 34030167171, 80103073519
OFFSET
1,1
COMMENTS
Row 4 of A302427.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +2*a(n-2) -a(n-3) +32*a(n-4) -21*a(n-5) -54*a(n-6) +18*a(n-7) -384*a(n-8) +170*a(n-9) +568*a(n-10) -141*a(n-11) +2355*a(n-12) -739*a(n-13) -3400*a(n-14) +626*a(n-15) -8500*a(n-16) +1993*a(n-17) +13579*a(n-18) -1666*a(n-19) +19582*a(n-20) -3652*a(n-21) -38275*a(n-22) +2196*a(n-23) -29263*a(n-24) +4898*a(n-25) +77920*a(n-26) +670*a(n-27) +25200*a(n-28) -5988*a(n-29) -116657*a(n-30) -8359*a(n-31) -2187*a(n-32) +9325*a(n-33) +130492*a(n-34) +16910*a(n-35) -26756*a(n-36) -15140*a(n-37) -110183*a(n-38) -19358*a(n-39) +41535*a(n-40) +18374*a(n-41) +70361*a(n-42) +13974*a(n-43) -36228*a(n-44) -15186*a(n-45) -33865*a(n-46) -6584*a(n-47) +21125*a(n-48) +8279*a(n-49) +12240*a(n-50) +2145*a(n-51) -8341*a(n-52) -2791*a(n-53) -3276*a(n-54) -488*a(n-55) +2128*a(n-56) +526*a(n-57) +611*a(n-58) +61*a(n-59) -323*a(n-60) -51*a(n-61) -66*a(n-62) -3*a(n-63) +27*a(n-64) +2*a(n-65) +3*a(n-66) -a(n-68) for n>69
EXAMPLE
Some solutions for n=5
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..1
..0..1..1..1..0. .1..1..0..1..0. .0..0..0..1..0. .0..1..0..1..0
..0..0..0..1..0. .0..1..0..1..0. .0..1..1..1..0. .1..0..0..1..0
CROSSREFS
Cf. A302427.
Sequence in context: A346783 A073619 A338820 * A292999 A374111 A216047
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 07 2018
STATUS
approved