18409

Appears in sequences

• G.f. A(x) satisfies: A(x) = exp( Sum_{k>=1} (-1)^(k+1) * A(x^k)^3 * x^k / k ).at n=7A052755
• Composite and every divisor (except 1) contains the digit 4.at n=8A062670
• Number of 5k+2 primes (A030432) in range [2^n,2^(n+1)].at n=19A095022
• Iccanobirt numbers (6 of 15): a(n) = R(a(n-1)) + R(a(n-2)) + a(n-3), where R is the digit reversal function A004086.at n=15A102116
• Iccanobirt semiprimes (6 of 15): Semiprime numbers in A102116.at n=2A102196
• Semiprimes in A056109.at n=35A113528
• a(n) = sum of the squares of the coefficients of x^n in x^(n-2*k)/A(x^2)^(n-2*k+1), as k varies from 0 to floor(n/2), with a(0)=1, where A(x) is the g.f. of this sequence.at n=16A132455
• Numbers n such that 4n+1 is a palindromic prime.at n=37A192261
• Number of partitions of n with difference 5 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=40A242696
• Linear divisibility sequence based on Salem number of order 4 (case t=6, see formula).at n=6A292034
• G.f.: A(x) = Sum_{n>=0} x^n * (1 + (-1)^n * A(x))^n / (1 - (-1)^n * x*A(x))^(n+1).at n=7A325157
• Numbers k such that k![4] - 256 is prime, where k![4] = A007662(k) = quadruple factorial.at n=35A329177
• a(n) = 12*n^2 + 4*n + 1.at n=39A381390
• Composite numbers that contain only nonprime digits and whose prime factors contain only nonprime digits.at n=35A383934