# Problem 554: Centaurs on a chess board On a chess board, a centaur moves like a king or a knight. The diagram below shows the valid moves of a centaur (represented by an inverted king) on an 8x8 board. It can be shown that at most n2 non-attacking centaurs can be placed on a board of size 2n×2n. Let C(n) be the number of ways to place n2 centaurs on a 2n×2n board so that no centaur attacks another directly. For example C(1) = 4, C(2) = 25, C(10) = 1477721. Let Fi be the ith Fibonacci number defined as F1 = F2 = 1 and Fi = Fi-1 + Fi-2 for i > 2. Find \$\\displaystyle \\left( \\sum\_{i=2}\^{90} C(F\_i) \\right) \\text{mod } (10\^8+7)\$.