20917

Appears in sequences

• Numbers k such that 93*2^k+1 is prime.at n=31A032396
• Gaps of 6 in sequence A038593 (lower terms).at n=5A038651
• Numbers whose base-12 representation has exactly 5 runs.at n=23A043654
• Semiprimes in A003215.at n=35A113530
• Ulam's spiral (SSW spoke).at n=36A143838
• a(n) = 12*n^2 + 18*n + 7.at n=41A154105
• Numbers k such that (2^k - k - 1)*2^k + 1 is prime.at n=20A201362
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 374", based on the 5-celled von Neumann neighborhood.at n=36A271459
• Numbers that are the sum of eight fourth powers in exactly eight ways.at n=28A345840
• E.g.f. A(x) satisfies A(x) = exp( x*(A(x) + A(w*x) + A(w^2*x))/3 ), where w = exp(2*Pi*i/3).at n=9A385691