A203971 Number of nX4 0..2 arrays with every 1 immediately preceded by 0 to the left or above, and every 2 immediately preceded by 0 1 to the left or above

7, 106, 2061, 34799, 601521, 10443081, 180623180, 3127443494, 54147787428, 937401735877, 16229119258691, 280969835877155, 4864330622552017, 84214645085725068, 1457981042829787092, 25241554445266482645

Offset

1,1

Comments

Column 4 of A203975

Links

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

Formula

Empirical: a(n) = 7*a(n-1) +65*a(n-2) +1532*a(n-3) +5728*a(n-4) +36988*a(n-5) -79954*a(n-6) -263553*a(n-7) -3722150*a(n-8) +3261200*a(n-9) +8444409*a(n-10) +152666516*a(n-11) -124486119*a(n-12) -492693233*a(n-13) -2755397610*a(n-14) +4009588292*a(n-15) +10293308252*a(n-16) +22336995885*a(n-17) -64924516938*a(n-18) -92755388359*a(n-19) -57474729030*a(n-20) +551610997114*a(n-21) +370469633714*a(n-22) -292081751432*a(n-23) -2630782090265*a(n-24) -301735948456*a(n-25) +2480960089737*a(n-26) +7374666257918*a(n-27) -2515766371859*a(n-28) -7296390671023*a(n-29) -12848715039718*a(n-30) +9261937257065*a(n-31) +11488496485545*a(n-32) +15234546948215*a(n-33) -14912487767600*a(n-34) -11435235548211*a(n-35) -13211824155401*a(n-36) +13970588762093*a(n-37) +7731108650320*a(n-38) +8675779656844*a(n-39) -8276900249091*a(n-40) -3561091877330*a(n-41) -4260429005786*a(n-42) +3209229435553*a(n-43) +1072805871492*a(n-44) +1506322359632*a(n-45) -828404552953*a(n-46) -194259086304*a(n-47) -368735917326*a(n-48) +143996746787*a(n-49) +16734372045*a(n-50) +60312985338*a(n-51) -17012881739*a(n-52) +289141565*a(n-53) -6324998526*a(n-54) +1368060305*a(n-55) -185095968*a(n-56) +399628198*a(n-57) -73289542*a(n-58) +13531943*a(n-59) -13912036*a(n-60) +2336844*a(n-61) -364629*a(n-62) +225419*a(n-63) -31536*a(n-64) +3130*a(n-65) -1258*a(n-66) +110*a(n-67)

Example

Some solutions for n=4
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1
..0..1..1..1....1..0..1..0....1..1..0..1....0..0..0..0....1..1..0..0
..0..2..0..2....0..0..1..2....0..2..0..2....1..1..1..0....2..2..1..1
..0..0..1..0....1..1..0..0....1..0..0..1....0..2..2..1....0..1..2..2

Crossrefs

Sequence in context: A209545 A002486 A360370 * A145167 A367166 A141358

Adjacent sequences: A203968 A203969 A203970 * A203972 A203973 A203974

Keyword

nonn

Author

R. H. Hardin Jan 08 2012

Status

approved