23669

Properties

Appears in sequences

• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=8A001990
• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=9A001990
• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=10A001990
• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=11A001990
• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=12A001990
• Let p be the n-th odd prime. a(n) is the least prime congruent to 5 modulo 8 such that Legendre(-a(n), q) = -Legendre(-2, q) for all odd primes q <= p.at n=13A001990
• Numbers k such that k*2^m-1 are composites for all exponents m in the range 0<=m<=k.at n=41A061154
• Near twin primes of order 18: twin primes (p, p+2) such that p+18 and p+20 are primes.at n=34A079304
• Number of B-trees of order infinity with n leaves, where a(n) = Sum_{k=1..floor(n/2)} a(k)*C(n-k-1,n-2*k) for n >= 2, with a(0)=0, a(1)=1.at n=20A119262
• A038601 type numbers where Prime of Prime numbers: a(n)=Prime[A038601 (n)].at n=8A144467
• a(1)=1. For n >= 2, a(n) = 2*a(n-1) + (number of composites among first n-1 terms of the sequence).at n=14A175104
• Number of lower triangles of a 3 X 3 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less.at n=23A195249
• Numbers k such that 3^k + 14 is prime.at n=25A219035
• The first position of the first cycle of sequence {b_k}={b_k}(n) in A237671.at n=17A238019
• Main diagonal of Ludic array A255127 (and A255129): a(n) = A255127(n,n).at n=25A255410
• Smallest of 4 consecutive prime numbers that when represented as a simple continued fraction, generates prime numbers in the numerator and denominator, when reduced.at n=19A270884
• Primes that can be generated by the concatenation in base 3, in ascending order, of two consecutive integers read in base 10.at n=30A287300
• Primes p such that p+2, (p+1)||p and (p+1)||(p+2) are primes (where || denotes concatenation in base 10).at n=29A309934
• First of three consecutive primes p,q,r such that r*(p+q) + p*q and r*(p+q) - p*q are prime.at n=38A358382
• Numbers k such that A073734(k) is neither squarefree nor a prime power.at n=9A365899