22707

Appears in sequences

• Discriminants of totally complex sextic fields (negated).at n=17A023687
• a(n) = n + (n+1)^2 + (n+2)^3.at n=26A027620
• Sum of the first n safe primes.at n=34A066869
• a(n) = (2*n-1)*(2*n+1)^2.at n=13A102094
• Numbers of the form p^2 * q^3, where p,q are distinct primes.at n=36A143610
• a(n) = n*(n+2)^2.at n=27A152619
• Odd numbers k such that A166100((k-1)/2)/k is not an integer.at n=25A166102
• Numbers of the form 20*k+7 which are three times a square.at n=17A192328
• G.f.: exp( Sum_{n>=1} A163659(n^2)*x^n/n ), where x*exp(Sum_{n>=1} A163659(n)*x^n/n) = S(x) is the g.f. of Stern's diatomic series (A002487).at n=27A195586
• Number of isomorphism classes of nanocones with 4 pentagons and a symmetric boundary of length n.at n=17A198015
• Number of (w,x,y,z) with all terms in {1,...,n} and w*x+y*z>n^2.at n=22A212136
• Numbers of the form p^2*q^3 where p, q are (not necessarily distinct) primes.at n=40A216417
• Sum of first n squares of semiprimes.at n=19A217736
• a(n) = smallest number k with property that if the base-n expansion of k is reversed, the result is a nontrivial multiple of k.at n=25A224220
• G.f. satisfies: A(x) = (1+x+x^2)^3 * A(x^2)^2.at n=13A237650
• a(n) = 27*n^2.at n=29A244634
• Achilles numbers which are coprime to the sum of their divisors.at n=32A248022
• Either 8th power of a prime, or product of a square and a cube of two different primes.at n=38A272191
• Numbers n such that for all divisors of n, ratios of 2 consecutive divisors of n will always reduce to lowest terms to a fraction with numerator=denominator+2.at n=24A280963
• Numbers that are the sum of three squares in arithmetic progression.at n=35A292313