23720

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 77.at n=26A031575
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 77.at n=1A031755
• T(2n+6,n), where T is the array in A055830.at n=4A055840
• Number of compositions of n into twin primes (i.e., primes that are members of a twin prime pair, like 3, 5, 7, 11, 13, but not 2 or 23).at n=45A077608
• Length of period of continued fraction for square root of -1 + n!.at n=12A078146
• Number of (n+1)X(n+1) 0..2 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock equal to the number in all its horizontal and vertical neighbors.at n=2A205047
• Number of (n+1)X4 0..2 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock equal to the number in all its horizontal and vertical neighbors.at n=2A205050
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the number of rightwards and downwards edge increases in each 2X2 subblock equal to the number in all its horizontal and vertical neighbors.at n=12A205055
• Number of polygon edges formed when every pair of vertices of a regular n-gon are joined by an infinite line.at n=19A344899
• Number of polygon edges formed when every pair of vertices of a regular 2n-gon are joined by an infinite line.at n=9A347322
• Number of partitions of n that do not have a fixed point that is also a fixed point of the conjugate partition.at n=39A374782