31954

Appears in sequences

• Sum of n plus its prime factors associated with A020700.at n=32A020905
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 14.at n=19A031602
• Numbers n such that 4*10^n + 2*R_n + 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=17A102985
• Numbers k such that (2^64 - 189)*10^k + 1 is prime.at n=10A209250
• Number of partitions of n such that (least part) <= (multiplicity of greatest part).at n=40A240179
• Number of acute triangles, distinct up to congruence, on a centered hexagonal grid of size n.at n=17A241232
• Number of (4+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 1 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 1 3 6 or 7.at n=8A252309
• G.f. A(x) satisfies A(x) = ( 1 + 4*x/(1 - x*A(x)) )^(1/2).at n=11A372016
• Expansion of (g/(2 - g^2))^2, where g = 1+x*g^2 is the g.f. of A000108.at n=6A391493