21379
domain: N
Properties
Primality
- Prime
- yes
Appears in sequences
- Primes p whose period of reciprocal equals (p-1)/7.at n=19A056212
- Prime(n) and prime(n+3) use the same digits.at n=25A069795
- Prime mean of 8 horizontal, vertical and main diagonal sums associated with primes in A094454.at n=26A094455
- Prime means of 12 horizontal, vertical and main diagonal sums associated with primes in A094458.at n=9A094459
- Expansion of 1 / ((1+x)*(1-2x)*(1-3x)*(1-4x)).at n=6A099110
- Primes that do not divide any term of the Lucas 4-step sequence A073817.at n=20A106300
- Numbers with d digits (d>0) which have at least 2d distinct primes as substrings.at n=16A168167
- Primes with nine embedded primes.at n=4A179917
- Prime numbers containing the digit string 137.at n=20A190307
- Number of n X n 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.at n=2A210780
- Number of nX3 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.at n=2A210783
- T(n,k)=Number of nXk 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.at n=12A210788
- Number of nX7 arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..2 nX7 array.at n=1A217963
- T(n,k)=Number of nXk arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..2 nXk array.at n=29A217964
- Number of 2Xn arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..2 2Xn array.at n=6A217965
- Primes formed from concatenation of PrimePi(n) and prime(n).at n=25A236551
- Greater of twin primes of (40n-23,40n-21).at n=28A244505
- The 180-degree spoke (or ray) of a hexagonal spiral of Ulam.at n=42A244806
- Initial primes of sets of 8 consecutive primes all different by modulo 30.at n=41A248199
- Prime-Indexed Primes (PIPs) k such that the sum of all PIPs <= k is a prime.at n=36A261148