27848

Appears in sequences

• Discriminants of totally complex sextic fields (negated).at n=24A023687
• Nonpalindromic numbers k such that k is not divisible by 10 and k*R(k) is a square, where R(k) is the reversal of k (A004086).at n=29A062917
• a(n) is the least index such that the least primitive root of the a(n)-th prime is n, or zero if no such prime exists.at n=50A066529
• Numbers k such that all the following properties hold: (i) k*reverse(k) is a square; (ii) k != reverse(k); (iii) k and reverse(k) are not both squares; and (iv) k and reverse(k) have the same number of digits.at n=18A082994
• Table T(n,k) = -2*T(n-1,k)+T(n-1,k+1) = T(n,k-4), 0<=n.at n=42A140287
• a(n+1)-+a(n)=prime, a(n+1)*a(n)=Average of twin prime pairs, a(1)=1,a(2)=4.at n=35A154493
• Members of A143610 for which both neighbors are squarefree.at n=16A166987
• Numbers of the form p^2*q^3 where p, q are (not necessarily distinct) primes.at n=43A216417
• Achilles numbers which are coprime to the sum of their divisors.at n=36A248022
• Either 8th power of a prime, or product of a square and a cube of two different primes.at n=41A272191
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 1006", based on the 5-celled von Neumann neighborhood.at n=39A273861
• Numbers k such that k | A047842(k).at n=11A278439
• Numbers n such that 2^n == 1 (mod sigma(n)).at n=22A278836
• a(1) = 27846; thereafter a(n+1) = a(n) # n, where # is an operation that cycles through division, addition, subtraction and multiplication.at n=2A327962
• Numbers k such that k, k + 1 and k + 2 have the same number of divisors in Eisenstein integers.at n=1A332387
• Achilles numbers that are deficient.at n=36A379164