50649

Appears in sequences

• n^3*a(n) is the number of circles in complex projective plane tangent to three smooth curves of degree n in general position.at n=35A030653
• Numbers k such that k!!! + 1 is prime (0 is included by convention).at n=45A037083
• a(1) = 1, a(n) is the smallest integer > a(n-1) such that the largest element in the simple continued fraction for S(n) = 1/a(1) + 1/a(2) + ... + 1/a(n) equals n^4.at n=3A070904
• Triangle read by rows: T(n,k) = 2*k*T(n-1,n-1) + 1 (n >= 0, 0 <= k <= n), with T(0,0) = 1.at n=25A161380
• Semiprimes q such that q^2-4 and q^2+4 are also semiprimes.at n=34A173084
• Main diagonal of A332357.at n=23A332358
• k such that 0 = Sum_{j=1..k} A373223(k, j). The indices of the rows in Gauss's triangle with vanishing row sums.at n=30A373181