70208

Appears in sequences

• Indices of primes in sequence defined by A(0) = 21, A(n) = 10*A(n-1) + 41 for n > 0.at n=10A101961
• Expansion of e.g.f. Product_{k>=1} ((1 + x^k)/(1 - x^k))^(1/k).at n=7A295792