Number of nX7 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.
A301661
Number of nX7 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.
Terms
- a(0) =21a(1) =22a(2) =46a(3) =89a(4) =223a(5) =696a(6) =2335a(7) =8380a(8) =31001a(9) =116558a(10) =442314a(11) =1686894a(12) =6453062a(13) =24725894a(14) =94832665a(15) =363935417a(16) =1397133323a(17) =5364622673a(18) =20601302508a(19) =79119265773a(20) =303870780015
External references
- oeis: A301661