18923

Appears in sequences

• n-th 4k+1 prime times n-th 4k-1 prime.at n=15A048630
• Composite numbers x such that sigma(x+120) = sigma(x)+120.at n=28A054985
• Triangle T(n,d) (listed row-wise: T(1,1)=1, T(2,1)=1, T(2,2)=1, T(3,1)=2, T(3,2)=2, T(3,3)=1, ...) giving the number of n-edge general plane trees with root degree d that are fixed by the four-fold application of Catalan Automorphisms A057511/A057512 (Deep rotation of general parenthesizations/plane trees).at n=66A079220
• Number of Catalan objects fixed by four-fold application of the Catalan bijections A057511/A057512 (Deep rotation of general parenthesizations/plane trees).at n=11A079225
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0100 pattern in any orientation.at n=16A146859
• Number of strings of numbers x(i=1..6) in 0..n with sum i^3*x(i) equal to 216*n.at n=19A184261
• Number of 0..n arrays x(0..10) of 11 elements with zero 5th differences.at n=47A200373
• Ulam numbers k such that 4*k and 16*k are also Ulam numbers.at n=26A287634
• Numbers k such that 4 is the smallest decimal digit of k^3.at n=28A291643
• a(n) = floor(cosh(n+1) - cosh(n)).at n=10A346169