18818

Appears in sequences

• a(0) = 1, a(n) = 24*n^2 + 2 for n>0.at n=28A010014
• a(n) = self-convolution of row n of array T given by A027113.at n=7A027134
• Numbers k such that sopf(k) = sopf(k+3), where sopf(k) = A008472(k).at n=22A063969
• Base 4 expansion of 1/n has equal percentage of each digit 0,1,2,3.at n=21A074709
• a(n) = 2*prime(n)^2.at n=24A079704
• a(0) = 3, a(1) = 8, a(n+2) = 4*a(n+1) - a(n) - 2.at n=7A102206
• a(n) = ((sqrt(3)+1)^n+(sqrt(3)-1)^n)^2/2^(n+1).at n=8A121401
• a(n) = 4*n^3 - 3*n^2 + 2*n - 1.at n=16A131464
• 2*p^2, for p an odd prime.at n=23A143928
• Nonnegative numbers n such that 6*2^n-1 is prime.at n=33A164523
• Partial sums of A006567.at n=37A172463
• Numbers consisting of ones and eights.at n=43A213084
• A modified Engel expansion for sqrt(3) - 1.at n=10A220335
• Composite numbers k such that Sum_{i=1..t-1} d(i+1)/d(i) is prime, where d(1), ..., d(t) are the divisors of k in ascending order.at n=23A255585
• Numbers of the form p * q^p where p and q are primes, in increasing order.at n=36A257404
• a(n) is the smallest composite k such that d(2)/d(1) + d(3)/d(2) + ... + d(q)/d(q-1) = prime(n), where d(1) < d(2) < ... < d(q) are the q divisors of k, or 0 if no such k exists.at n=26A260901
• Numbers k such that k and k^2 are the sums of two nonzero squares in exactly two ways.at n=35A273293
• Numbers n such that there are precisely 5 groups of orders n and n + 1.at n=41A295991
• Where records occur in A070138.at n=25A298942
• Number of partitions of n having an integer median.at n=36A325347