47965

Appears in sequences

• Fibonacci sequence beginning 4,9.at n=19A022130
• Number of 2 X 2 regular integer matrices with elements from {0,...,n} up to row and column permutation.at n=20A064363
• Numbers k such that 7^k + 5^k - 1 is prime.at n=17A101234
• Values of x in the solutions to x^2 - 3xy + y^2 + 29 = 0, where 0 < x < y.at n=20A218735
• Irregular triangular array: row n gives numbers D, each being the discriminant of the minimal polynomial of a quadratic irrational represented by a continued fraction with period an n-tuple of 1s and 3s.at n=45A246921
• Irregular triangular array: every periodic simple continued fraction CF represents a quadratic irrational (c + f*sqrt(d))/b, where b,c,f,d are integers and d is squarefree. Row n of this array shows the distinct values of d as CF ranges through the periodic continued fractions having period an n-tuple of 1s and 3s.at n=45A246922
• Triangle T(n,k), n >= 2, 0 <= k <= floor(n^2/2)-2*n+2, read by rows, where T(n,k) is the number of 2*(k+2*n-2)-cycles in the n X n grid graph which pass through four corners ((0,0), (0,n-1), (n-1,n-1), (n-1,0)).at n=23A333668