30859

Properties

Appears in sequences

• Number of rooted planar trees where any 2 subtrees extending from same node have a different number of nodes.at n=13A032010
• Primes followed by a [10,2,10] prime difference pattern of A001223.at n=29A052376
• Primes p such that the left prime neighbors p1, p2 of p as well as the right prime neighbors q1, q2 of p form twin prime pairs and the sum p1 + p2 + p + q1 + q2 is also prime.at n=23A138396
• Primes p such that continued fraction of (1 + sqrt(p))/2 has period 6: primes in A146331.at n=29A146351
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 0), (-1, 1), (0, 1), (1, -1)}.at n=12A151401
• Primes of the form 9n^2-8n+2.at n=11A154253
• Least prime p = 1 (mod n) which divides Fibonacci((p-1)/n).at n=36A168171
• Smallest emirp corresponding to A178585.at n=29A178586
• Primes p(n) such that p(n) + p(n+3) = p(n+1) + p(n+2) and p(n) + p(n+4) = p(n+2) + p(n+3).at n=25A266882
• G.f.: [ Sum_{n>=0} x^n * (1+x)^(n^2) ] * [ Sum_{n>=0} x^n / (1+x)^(n^2) ].at n=9A320950
• Primes that are palindromes in primorial base.at n=25A333424
• Primes p such that 2*p-1 and (2*p-1)^2+(2*p)^2 are also prime.at n=34A347165
• Discriminants of imaginary quadratic fields with class number 41 (negated).at n=37A351679
• Number of compositions of n such that the maximal cardinality of C is 1, where C is a subset of the set of parts such that all elements in C appear in weakly increasing order within the composition.at n=17A387371
• a(n) = Sum_{k=0..n} binomial(n+3*k+2,k).at n=5A390471
• Prime numbersat n=3328