56921

Properties

Appears in sequences

• Beginning with 3, least prime such that concatenation of first n terms and its digit reversal both are primes.at n=43A113584
• Primes of the form k^2 + k + 55661, with k >= 0.at n=26A116206
• Primes p such that p+2, n*(p+2)+6 and p*(p+2)+8 are also prime.at n=8A130735
• Number of n X 3 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.at n=8A202974
• T(n,k)=Number of nXk 0..1 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors.at n=57A202979
• Prime p such that p^5 + p^3 + p - 4 and p^5 + p^3 + p + 4 are primes.at n=44A243900
• Prime numbersat n=5772