Number of 2Xn 0..2 arrays with exactly floor(2Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order.
A222691
Number of 2Xn 0..2 arrays with exactly floor(2Xn/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order.
Terms
- a(0) =0a(1) =3a(2) =4a(3) =18a(4) =56a(5) =237a(6) =784a(7) =3218a(8) =11152a(9) =45290a(10) =161696a(11) =650010a(12) =2372368a(13) =9467136a(14) =35149184a(15) =139387576a(16) =524385184a(17) =2070069588a(18) =7866603584a(19) =30953957824a(20) =118536117440a(21) =465439834288
External references
- oeis: A222691