51695

Appears in sequences

• a(n) = Sum_{i=0..n} digsum_9(i)^4, where digsum_9(i) = A053830(i).at n=30A231687
• Numbers n such that abs(n - 4^k) is prime for k = 1..8.at n=13A281047
• a(n) = a(n-1) + a(n-2) + a([n/2]), where a(0) = 1, a(1) = 2, a(2) = 3.at n=20A298339