240021

Appears in sequences

• E.g.f. satisfies A(x) = exp(x*A(x^3/3!)).at n=11A143567
• Expansion of Product_{k>=1} 1/(1 - (4*k-1)*x^(4*k-1)).at n=33A265828
• T(n,k) is the number of 4-ary strings of length n+1 with k+1 indispensable digits and a nonzero leading digit with 0 <= k <= n.at n=49A340620
• T(n,k) is the number of 4-ary strings of length n+1 with k+1 indispensable digits and a nonzero leading digit with 0 <= k <= n.at n=50A340620
• Expansion of e.g.f. exp( x * exp(x^3/6) ).at n=11A354551
• Nonprime numbers k for which k*k' is a palindrome, where k' is the arithmetic derivative of k (A003415).at n=27A359331