40742

Appears in sequences

• Numbers k such that 15*2^k - 1 is prime.at n=33A002237
• Indices of primes in sequence defined by A(0) = 81, A(n) = 10*A(n-1) + 31 for n > 0.at n=17A101066
• a(n) = Sum {k + j*m <= n} (k + j*m), with 0 < k,j,m <= n.at n=33A106847