31711

Appears in sequences

• Number of pairs of permutations of degree n that avoid (12,21).at n=6A007767
• Numbers k such that 153*2^k-1 is prime.at n=39A050618
• Number of ordered quintuples (a,b,c,d,e) with gcd(a,b,c,d,e)=1 (1<= {a,b,c,d,e} <= n).at n=7A082544
• a(n) = n^3 - n^2 - n - 1.at n=32A083074
• Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 4 and repeat; as m = 1,2,3,.. the remaining terms form this sequence.at n=14A112562
• a(n) = A000045(n) + A113405(n).at n=18A140428
• Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in an em 1,1 1,2 2,2 2,3 3,3 in any orientation.at n=13A146150
• Collatz trajectory starting at 3711.at n=15A179623
• Numerator of the cumulative frequency of the dropping time in the Collatz iteration.at n=10A186109
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 305", based on the 5-celled von Neumann neighborhood.at n=36A271162
• a(n) = Sum_{d|n} (-1)^(n/d+1)*d^5.at n=7A284926
• G.f. satisfies A(x) = 1 + x^3*A(x)^2 / (1 - x*A(x)).at n=19A365694
• a(n) = Sum_{1 <= x_1, x_2, x_3, x_4 <= n} n/gcd(x_1, x_2, x_3, x_4, n).at n=7A372961
• Lexicographically earliest sequence of positive integers a(1), a(2), a(3), ... such that for any n > 0, Sum_{k = 1..n} prime(k)/a(k) < 1.at n=3A375529