25171

Properties

Appears in sequences

• Number of partially achiral planted trees with n nodes.at n=20A003237
• Certain subgraphs of a directed graph.at n=4A005332
• a(1) = 2; a(n) is the smallest prime > a(n-1) such that a(n) + a(n-1) is a square.at n=23A062064
• Boustrophedon transform of ((-2)^n+0^n)/2.at n=10A097953
• Middle of 3 consecutive prime numbers such that p1*p2*p3 + d1 + d2 - 1 = average of twin prime pairs, d1 (delta) = p2 - p1, d2 (delta) = p3 - p2.at n=9A153404
• Primes p such that p*floor(p/2)-2 and p*floor(p/2)+2 are also prime numbers.at n=33A164621
• Numbers n with property that (n+1)*prime(n+1)-n*prime(n) is a perfect square s^2.at n=38A181283
• Number of 5-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and first and second differences in -n..n.at n=27A208972
• Triangle read by rows: coefficients psi(n,k) arising from the study of completely transitive graphs on n nodes.at n=16A259972
• Smallest prime in the sequence s(k) = n*s(k-1) - s(k-2), with s(0) = 1, s(1) = n + 1 (or -1 if no such prime exists).at n=28A269253
• Primes that can be generated by the concatenation in base 6, in descending order, of two consecutive integers read in base 10.at n=16A287307
• Smallest prime p such that the Diophantine equation x + y + z = p with x*y*z = k^3 (0 < x <= y <= z) has exactly n solutions.at n=35A290401
• The excess of the number of partitions of n with more odd parts than even parts over the number of partitions of n with more even parts than odd parts.at n=43A338860
• Number of compositions (ordered partitions) of n into distinct parts >= 5.at n=51A339103
• Discriminants of imaginary quadratic fields with class number 41 (negated).at n=30A351679
• For n >= 1, a(n) is the least prime p such that the arithmetic mean of (n + 1) consecutive primes starting with p is a perfect square, or a(n) = -1 if no such p exists.at n=19A365706
• Number of edges in the directed graph for the Reversed Zeckendorf game with starting number n.at n=51A389617
• Prime numbersat n=2779