31151

Properties

Appears in sequences

• Primes with all odd digits such that the next three primes also contain all odd digits.at n=21A068831
• Primes p of the form k*(k + 1) - 1 such that p and p + 2 are twin primes.at n=23A088486
• Primes A005382(n) + A005384(n) - 1 with a twin prime A005382(n) + A005384(n) + 1.at n=35A099109
• Total sum of parts of multiplicity 1 in all partitions of n.at n=26A103628
• Prime numbers n such that A127350(k) = 2*n for some k.at n=2A127351
• Least prime P such that P^(2*prime(n))-P^prime(n)-1 is prime with prime(n) the n-th prime.at n=44A131580
• Numbers such that the digital sum base 2 and the digital sum base 3 and the digital sum base 10 all are equal.at n=34A135120
• a(1) = 3. For n > 1, Ulam's spiral is started with a(n-1), and the primes p on the NE spoke are considered. a(n) is the minimal p that is the lesser of a twin prime pair.at n=33A163586
• Primes p of the form 4*k+3 such that p+2 is prime and p-1 is nonsquarefree.at n=28A175606
• Least prime q satisfying q^p == 1 (mod 2p+1) and p^q == 1 (mod 2q+1), or 0 if otherwise, where p = prime(n).at n=63A220295
• Primes of the form n^2-n-1 (for some n) such that p^2-p-1 is also prime.at n=21A237642
• Lesser of consecutive primes whose average is an oblong number.at n=43A242383
• Twin prime pairs of the form (k^2 + k - 1, k^2 + k + 1).at n=46A265006
• Initial member of 6 consecutive primes a, b, c, d, e, f such that both (f + a)/(d - c) and (e + b)/(d - c) are prime.at n=15A293619
• Primes p such that q = p mod A001414(p-1) = p mod A001414(p+1) is prime.at n=29A339182
• Primes p such that 2*p+1 and (2*p)^2+(2*p+1)^2 are also prime.at n=34A347110
• Numerators of the partial sums of the reciprocals of the Dedekind psi function (A001615).at n=28A357818
• 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=44A358382
• Prime numbersat n=3355