17988

Appears in sequences

• Sums of terms of groups in A075621.at n=32A075625
• Starting positions of strings of three 9's in the decimal expansion of Pi.at n=14A083642
• Starting positions of strings of four 9's in the decimal expansion of Pi.at n=3A083643
• Position of the first occurrence of exactly n consecutive '9's in a row in the decimal expansion of Pi.at n=3A096763
• G.f.s of the z^p coefficients of the polynomials in the GF3 denominators of A156927.at n=15A157704
• Number of binary strings of length n with no substrings equal to 000 or 011.at n=30A164315
• Expansion of x*(1+x+x^2) / ( (x-1)*(x^3+x^2-1) ).at n=30A171861
• Initial members of abundant quadruplets, i.e., values of k such that (k, k+2, k+4, k+6) are all abundant numbers.at n=28A231089
• Number of (n+2) X (2+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00010101 00100101 or 01010101.at n=10A261259
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 358", based on the 5-celled von Neumann neighborhood.at n=41A271412
• a(n) = Sum_{1 <= i, j, k <= n} gcd(i,j,k).at n=23A344522