18461
domain: N
Properties
Primality
- Prime
- yes
Appears in sequences
- a(n) = prime(n^2).at n=45A011757
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite BOG = Boggsite Na4Ca7[Al18Si78O192].74H2O starting with a T6 atom.at n=13A019078
- Lower prime of a difference of 20 between consecutive primes.at n=36A031938
- Least prime in A031938 (lesser of primes differing by 20) whose distance to the next 20-twin is 6*n.at n=22A052359
- Floor(X/Y) where X = concatenation of (2n), (2n-1), ... down to n+1 and Y = concatenation of n, n-1, n-2, ... down to 1.at n=6A067089
- Number of elements e in all partitions of n such that e divides n.at n=28A089251
- Primes of the form [prime(n)*prime(n+1)+p]/2 with increasing p.at n=40A100558
- Primes p such that 2p+1, 4p+3, 6p+5 are all primes.at n=18A107020
- Primes p2 such that p1^2 + p2^3 is an average of twin primes and p1 < p2 are consecutive primes.at n=19A138716
- Primes congruent to 53 mod 59.at n=35A142780
- Primes congruent to 39 mod 61.at n=31A142837
- Primes of the form : 2*p+1=p1(prime), 2*p1+3=p2(prime), 2*p2+5=p3(prime).at n=35A143912
- A144325(n) + A144313(n) + A144315(n).at n=37A144715
- Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1001-1111 pattern in any orientation.at n=13A147408
- Sum of proper divisors minus the number of proper divisors of Catalan number A000108(n).at n=10A152988
- Prime number that appears the most often as the n-th prime factor of an integer in a factorization given in ascending order.at n=13A194156
- Number of dominating subsets of the theta-graph TH(2,2,n) (n>=1). A tribonacci sequence with initial values 13, 23, and 41.at n=12A213655
- a(n) is the position of the last two-tuple within the reverse lexicographic set of partitions of 2n and 2n+1, with a(1)-a(n) representing the positions of every 2-tuple partition of 2n and 2n+1.at n=28A216053
- Primes of the form 2*n^2+38*n+17.at n=36A243890
- "Convex" primes: extremal primes in the sense of Tutaj.at n=25A246033