51537

Appears in sequences

• Number of integers <= 2^n of form 4 x^2 + 4 x y + 5 y^2.at n=19A000076
• Number of length 5+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=37A248438
• Numbers k such that (26*10^k - 503)/9 is prime.at n=21A296051
• Numbers k such that the k-th triangular number is a binary palindrome.at n=45A350988