40665

Appears in sequences

• Numbers k such that 7*(10^k - 1)/9 - 10^floor(k/2) is a palindromic wing prime (a.k.a. near-repdigit palindromic prime).at n=9A077788
• a(n) = K(n-1) + K(n) + K(n+1), where K(n) = A341711(floor(n/2)).at n=19A361151
• a(n) = Sum_{k=0..n} 4^k * binomial(n,k) * binomial(n+1,k).at n=5A388060