23201

Properties

Appears in sequences

• Values of m in the discriminant D = -4*m leading to a new maximum of the L-function of the Dirichlet series L(1) = Sum_{k=1..oo} Kronecker(D,k)/k.at n=26A003420
• Smallest nontrivial extension of n-th palindrome which is a prime.at n=31A030675
• Base-4 numbers whose list of divisors (in base 4) contains each digit 0-3 the same number of times.at n=4A045813
• n written efficiently in natural numbers base, i.e., in form ...wxyz where n = 1*z + 2*y + 3*x + 4*w + ... with z <= 1, y < 2, x < 3, w < 4, ...at n=28A055611
• Floor((Product of composite numbers up to n)/(product of primes up to n)).at n=15A073699
• Primes p such that sum of squares of even-position digits equals the sum of squares of odd-position digits of p.at n=7A076168
• 8th binomial transform of the periodic sequence (1,9,1,1,9,1...).at n=4A081035
• a(n) is the smallest lesser of twin prime p, such that prime(2 + p) - prime(p) = 2n (cf. A096474).at n=33A096475
• a(n) = 58*n^2 + 1.at n=20A158666
• Primes that can be written as a sum of a positive square and a positive cube in more than one way.at n=38A162930
• a(1) = 3. For n > 1, Ulam's spiral is started with a(n-1), and the primes p on the NE spoke are considered. a(n) is the minimal p that is the lesser of a twin prime pair.at n=29A163586
• Numbers such that n^2 = 29 mod 1193.at n=38A165989
• Primes that become squares when prefixed with a 1.at n=2A167734
• The n-th prime number that equals 1 (mod 4n).at n=39A203018
• Poly-Cauchy numbers of the second kind -hat c_3^(-n).at n=6A223906
• Primes of the form 232*m^2+1.at n=7A230392
• Primes p such that p+2 and q are primes, where q is concatenation of binary representations of p and p+2: q = p * 2^L + p+2, where L is the length of binary representation of p+2: L=A070939(p+2).at n=31A232238
• Primes p with P(p+1) also prime, where P(.) is the partition function (A000041).at n=15A234900
• Numbers k such that prime(k) * 2^k + 1 is prime.at n=18A239742
• Greatest prime factor of n^5 + 1.at n=41A240548