Number of nX4 0..1 arrays with every element unequal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
A318210
Number of nX4 0..1 arrays with every element unequal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
Terms
- a(0) =2a(1) =10a(2) =21a(3) =69a(4) =245a(5) =698a(6) =2321a(7) =7528a(8) =24531a(9) =80826a(10) =263430a(11) =865328a(12) =2842893a(13) =9337446a(14) =30698901a(15) =100854560a(16) =331565806a(17) =1089746855a(18) =3582297494a(19) =11775723803a(20) =38708636705a(21) =127247937304a(22) =418290582504
External references
- oeis: A318210