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A251917 Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum 2 4 5 or 7 and every diagonal and antidiagonal sum not 2 4 5 or 7 1
1914, 3054, 4624, 4938, 10704, 19964, 34396, 76834, 157770, 319716, 740790, 1685004, 3846896, 9112670, 21481768, 50721208, 121511664, 290632366, 695789488, 1673868150, 4026097838, 9684997378, 23347339456, 56274247106, 135653112384 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A251923

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 2*a(n-1) +32*a(n-3) -47*a(n-4) -23*a(n-5) -440*a(n-6) +343*a(n-7) +642*a(n-8) +3413*a(n-9) +588*a(n-10) -7308*a(n-11) -16536*a(n-12) -25667*a(n-13) +41740*a(n-14) +52393*a(n-15) +186768*a(n-16) -102638*a(n-17) -105643*a(n-18) -689747*a(n-19) -128440*a(n-20) +65369*a(n-21) +1280423*a(n-22) +1603575*a(n-23) +539189*a(n-24) -136708*a(n-25) -4265738*a(n-26) -2604698*a(n-27) -5150241*a(n-28) +2997077*a(n-29) +5332802*a(n-30) +12333661*a(n-31) +9336476*a(n-32) -2405377*a(n-33) -12409108*a(n-34) -25817624*a(n-35) -12305820*a(n-36) -78297*a(n-37) +24743640*a(n-38) +27867445*a(n-39) +16214136*a(n-40) -2916474*a(n-41) -23518833*a(n-42) -20986543*a(n-43) -13970868*a(n-44) +3704091*a(n-45) +11763865*a(n-46) +11754761*a(n-47) +7138800*a(n-48) -719074*a(n-49) -3128378*a(n-50) -4425844*a(n-51) -2624296*a(n-52) -792382*a(n-53) +406114*a(n-54) +1223686*a(n-55) +928430*a(n-56) +403224*a(n-57) -190568*a(n-58) -324084*a(n-59) -148672*a(n-60) +6344*a(n-61) +50496*a(n-62) +19952*a(n-63) +480*a(n-64) -2880*a(n-65) -960*a(n-66) for n>69

EXAMPLE

Some solutions for n=4

..1..3..0..2....3..2..2..0....3..2..0..3....3..2..2..0....2..1..1..2

..3..1..3..0....0..2..0..3....3..0..2..2....2..1..1..2....1..1..3..3

..0..3..1..3....2..0..3..1....1..3..0..2....0..2..2..3....1..3..0..2

..2..0..3..1....3..3..1..1....1..1..3..3....0..2..2..0....3..0..2..0

..0..2..0..3....0..1..1..2....2..1..1..0....2..1..1..2....0..2..0..3

..3..2..2..1....1..1..2..2....2..2..1..1....0..2..2..0....2..0..3..1

CROSSREFS

Sequence in context: A163678 A175517 A163863 * A222928 A309031 A077087

Adjacent sequences:  A251914 A251915 A251916 * A251918 A251919 A251920

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 11 2014

STATUS

approved

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Last modified August 10 22:36 EDT 2022. Contains 356046 sequences. (Running on oeis4.)