21739

Properties

Appears in sequences

• Prime lucky numbers k (from A031157) such that nextprime(k)=nextlucky(k).at n=28A057698
• a(n) = floor(10^n/7^n).at n=28A094992
• Balanced primes of order six.at n=17A096698
• Numbers p such that p = (prime(n)+ prime(n+3))/2 is prime for prime indices n=2, 3, 5...at n=23A098039
• Primes which are triangular numbers plus 3.at n=20A159047
• Numbers k such that (8^k + 7^k)/15 is prime.at n=13A181141
• Total number of distinct nilpotent subgroups of the alternating group, counting conjugates as distinct.at n=7A218943
• Primes p with same last two digits as k, where prime(k) = p.at n=24A232102
• 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=33A232237
• Number of partitions of n for which 2*(number of distinct parts) > (number of parts).at n=43A237365
• Greater of twin primes of (40n-23,40n-21).at n=29A244505
• Number of (n+2) X (6+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.at n=17A258964
• Prime numbers p such that p - 2, p^2 - p - 1, p^2 - p + 1 are prime numbers.at n=9A274525
• Values of odd prime numbers, D, for incrementally largest values of minimal x satisfying the equation x^2 - D*y^2 = -2.at n=35A336790
• Values of odd prime numbers, D, for incrementally largest values of minimal positive y satisfying the equation x^2 - D*y^2 = -2.at n=34A336792
• Twin primes p such that the absolute difference of p and the reverse of its twin is a twin prime.at n=45A342216
• Bitwise encoding of the state of a 1D cellular automaton after n steps from ...111000... where adjacent cells swap 01 <-> 10 when within triples 110 or 011.at n=30A359303
• Prime numbersat n=2439