A264474 Number of (n+1)X(6+1) arrays of permutations of 0..n*7+6 with each element having directed index change 0,1 1,0 2,1 or -1,-1.

0, 36, 160, 2272, 28489, 310748, 3842048, 43644384, 505769648, 5849013488, 67135006848, 774054696448, 8896767499776, 102334987567872, 1176757087435008, 13529311221840896, 155560070455705600, 1788454272171147264

Offset

1,2

Comments

Column 6 of A264476.

Links

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

Formula

Empirical: a(n) = 12*a(n-1) +48*a(n-2) -400*a(n-3) -4048*a(n-4) +11008*a(n-5) +78144*a(n-6) +130560*a(n-7) -1737728*a(n-8) +404992*a(n-9) -2965248*a(n-10) +63133696*a(n-11) -237834240*a(n-12) +595820544*a(n-13) -2770386944*a(n-14) +13195608064*a(n-15) -29207560192*a(n-16) +119052697600*a(n-17) -486106202112*a(n-18) +1221473599488*a(n-19) -4705283473408*a(n-20) +13249705672704*a(n-21) -32820932116480*a(n-22) +110719425052672*a(n-23) -236031269928960*a(n-24) +531386238763008*a(n-25) -1555418111279104*a(n-26) +2696466367774720*a(n-27) -5226184925249536*a(n-28) +13099581533323264*a(n-29) -18769762997764096*a(n-30) +29251407345352704*a(n-31) -60587488736968704*a(n-32) +67342888178024448*a(n-33) -70931694131085312*a(n-34) +112589990684262400*a(n-35) -72057594037927936*a(n-36) for n>40

Example

Some solutions for n=4
..8..0.10..2..3.13..5....8..9.10..2..3.13..5....8..0..1.11.12..4..5
.15..1.17..9..4.20..6....0..1.17.18..4.20..6...15.16..2.18.10.20..6
..7.23.24.25.11.12.19...22.14.15.25.11.27.19....7.23..9.25..3.27.13
.14.30.22.32.33.34.26...29..7.16.32.24.34.12...14.30.22.17.33.34.26
.21.28.29.16.31.18.27...21.28.23.30.31.26.33...21.28.29.24.31.32.19

Crossrefs

Cf. A264476.

Sequence in context: A064244 A280397 A064500 * A338390 A268905 A017054

Adjacent sequences: A264471 A264472 A264473 * A264475 A264476 A264477

Keyword

nonn

Author

R. H. Hardin, Nov 14 2015

Status

approved