20677

Appears in sequences

• Expansion of Product_{i>=1} (1 - x^i)^(-1/i); also of exp(Sum_{n>=1} (d(n)*x^n/n)) where d is number of divisors function.at n=7A028342
• "AGK" (ordered, elements, unlabeled) transform of 1,3,5,7...at n=10A032026
• Base-8 palindromes that start with 5.at n=21A043025
• Product of 3 successive primes.at n=8A046301
• Numbers k such that phi(sigma(phi(k))) = sigma(k).at n=8A066462
• Numerator of coefficient of (-x^2)^n in F(x)*F(-x) where F(x) = Sum_{k>=0} x^k/(k!)^3.at n=11A068113
• Lexicographically earliest sequence of pairwise coprime numbers such that tau(a(n)) = n, where tau(k) = number of divisors of k.at n=7A086556
• Numerators of series expansion of the e.g.f. for the Catalan numbers.at n=18A144186
• Triangle of coefficients of g.f. a*(1+x)^n + b*(1-x)^(n+2)*polylog(-n-1, x)/x + 2^n*c*(1-x)^(n+1)*LerchPhi(x, -n, 1/2), with a = -1, b = 1, c = 1.at n=46A168523
• Triangle of coefficients of g.f. a*(1+x)^n + b*(1-x)^(n+2)*polylog(-n-1, x)/x + 2^n*c*(1-x)^(n+1)*LerchPhi(x, -n, 1/2), with a = -1, b = 1, c = 1.at n=53A168523
• G.f.: Sum_{n>=0} x^n * Product_{k=0..n-1} (1 + k*x + x^2).at n=12A201951
• S_11 sequence in partition of integers > 1 described in A240521.at n=11A241024
• Numbers that are products of at least three consecutive primes.at n=14A257891
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f.: Product_{j>0} 1/(1-j^k*x^j)^(1/j).at n=35A294761
• Denominators of Harary index for the n-permutation star graph.at n=21A296057
• Smallest b > 1 such that b^(p-1) == 1 (mod p^4) for p = prime(n).at n=12A353937
• a(n) = A061300(n+1)/A061300(n).at n=7A357582
• Products m of k = 3 consecutive primes p_1..p_k, where only p_1 < m^(1/k).at n=3A375008
• Number of integer partitions of n whose first differences are not all distinct.at n=37A389919