A266103 Number of 3 X n integer arrays with each element equal to the number of horizontal and antidiagonal neighbors exactly one smaller than itself.
1, 16, 64, 161, 736, 3846, 16103, 62778, 274466, 1238762, 5293041, 22276043, 96335136, 419550430, 1803305352, 7726652568, 33323635453, 143929545318, 619694522447, 2666428933331, 11491110825839, 49536410438938
Offset: 1
Keywords
Examples
Some solutions for n=4: ..1..0..1..1....1..0..0..0....0..0..0..0....0..0..0..1....1..0..1..2 ..0..2..0..0....0..0..2..1....1..2..0..0....0..0..1..1....0..2..1..1 ..1..0..0..1....1..1..0..0....1..0..0..0....1..2..0..0....0..0..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A266101.
Formula
Empirical: a(n) = 4*a(n-1) +10*a(n-3) +60*a(n-4) -241*a(n-5) -275*a(n-6) -275*a(n-7) -1906*a(n-8) +266*a(n-10) +23553*a(n-11) +69768*a(n-12) -50662*a(n-13) -109039*a(n-14) -248005*a(n-15) -977832*a(n-16) +907466*a(n-17) +5373976*a(n-18) +8491160*a(n-19) +9435986*a(n-20) +1644865*a(n-21) -7010416*a(n-22) -13190485*a(n-23) -19551301*a(n-24) -9946324*a(n-25) -6037790*a(n-26) +3234342*a(n-27) +10883758*a(n-28) -1052994*a(n-29) +7949179*a(n-30) -1563048*a(n-31) +1098828*a(n-32) +11920090*a(n-33) +5977957*a(n-34) +20415705*a(n-35) +3449370*a(n-36) -7285989*a(n-37) -8698518*a(n-38) -13671771*a(n-39) -4863001*a(n-40) -5896817*a(n-41) -1867155*a(n-42) +2201749*a(n-43) +3172499*a(n-44) +3923456*a(n-45) +1976757*a(n-46) +1117259*a(n-47) +326318*a(n-48) -477791*a(n-49) -602510*a(n-50) -384845*a(n-51) -145647*a(n-52) -80645*a(n-53) -45723*a(n-54) +11145*a(n-55) +31554*a(n-56) +13446*a(n-57) +4398*a(n-58) +2741*a(n-59) -52*a(n-60) -526*a(n-61) -71*a(n-62) +19*a(n-63) +3*a(n-64) for n>68.
Comments