23127

Appears in sequences

• Numbers whose base-5 representation contains exactly three 0's and three 2's.at n=26A045187
• a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=39A050031
• Minimal m such that n^n-m and n^n+m are both primes, or -1 if there is no such m.at n=42A075468
• Total number of palindromic primes in base 2 below 2^n.at n=34A117772
• Total number of palindromic primes in base 2 below 2^n.at n=35A117772
• Numbers k such that k^6 - 2 and k^6 + 2 are both primes.at n=32A154938
• Wiener index of the n-web graph.at n=25A180576
• Number of length 5 nonnegative integer arrays starting and ending with 0 with adjacent elements unequal but differing by no more than n.at n=25A205342
• Number of n X 2 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, rows lexicographically nondecreasing, and columns lexicographically nonincreasing.at n=24A229422
• a(n) = Sum_{k=1..n} k * A088370(n,k).at n=44A309371
• Numbers k such that 387*2^k+1 is prime.at n=23A323038
• a(n) = number of partitions p of n such that the greatest multiplicity of the parts of p is not a part of p.at n=40A365616
• Number of vertices in a complete bipartite graph where the vertices in the two parts are placed on opposite sides of a parabola at integer y coordinates y = 1, 2, ...n.at n=17A392442