Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.
A253218
Number of n X 3 nonnegative integer arrays with upper left 0 and lower right its king-move distance away minus 2 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =19a(4) =102a(5) =263a(6) =504a(7) =825a(8) =1226a(9) =1707a(10) =2268a(11) =2909a(12) =3630a(13) =4431a(14) =5312a(15) =6273a(16) =7314a(17) =8435a(18) =9636a(19) =10917a(20) =12278a(21) =13719a(22) =15240a(23) =16841a(24) =18522a(25) =20283a(26) =22124a(27) =24045a(28) =26046a(29) =28127
External references
- oeis: A253218