A163038 Number of nX3 binary arrays with all 1s connected and a path of 1s from left column to right column

1, 17, 144, 920, 5191, 27651, 143342, 733512, 3730303, 18914231, 95766768, 484557538, 2450951157, 12395284963, 62682479764, 316971668262, 1602829696167, 8104958759329, 40983832221302, 207239970377650, 1047934399198859

Offset

1,2

Links

R. H. Hardin, Table of n, a(n) for n=1..62

Formula

Empirical: a(n)= 12*a(n-1) -54*a(n-2) +121*a(n-3) -144*a(n-4) +72*a(n-5) +38*a(n-6) -82*a(n-7) +41*a(n-8) +4*a(n-9) -8*a(n-10) +a(n-11). G.f.: -x*(1+5*x-6*x^2-11*x^3+14*x^4-9*x^5-2*x^6-x^7+x^8) /( (x^2+2*x-1) *(x^6-7*x^5 +x^4+6*x^3-11*x^2+7*x-1) *(x-1)^3). [From R. J. Mathar, Aug 11 2009]

Crossrefs

Sequence in context: A228254 A376459 A304207 * A216422 A008417 A241796

Adjacent sequences: A163035 A163036 A163037 * A163039 A163040 A163041

Keyword

nonn

Author

R. H. Hardin Jul 20 2009

Status

approved