18280

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 67.at n=36A031565
• Area of all nondecreasing Dyck paths of length 2n.at n=7A061648
• Expansion of (1 - x)^(-1)/(1 + 2*x - 2*x^2 + x^3).at n=10A077918
• a(n) = floor(e*(n+3)!) - (n+3)*(n+2)*(n+1)*n*floor(e*(n-1)!).at n=23A080770
• Coefficients of a generalized Jaco-Lucas polynomial (even indices) read by rows.at n=38A122076
• a(n) = n^3 - 2*n^2 + 2*n + 1.at n=26A188947
• Least happy number with next happy number of distance n.at n=31A193573
• Difference between the sum of odd parts and the sum of even parts in all the partitions of n.at n=32A208477
• Number of length n+3 0..2 arrays with no four elements in a row with pattern abab (with a!=b) and new values 0..2 introduced in 0..2 order.at n=7A243038
• T(n,k)=Number of length n+3 0..k arrays with no four elements in a row with pattern abab (with a!=b) and new values 0..k introduced in 0..k order.at n=43A243044
• Number of 4-cycles in the Lucas cube Lambda(n).at n=16A245961
• a(n) = smallest m such that A031131(m) = 2*n.at n=44A261525
• Expansion of psi(-x^3) / f(-x) in powers of x where psi(), f() are Ramanujan theta functions.at n=44A271593
• Numbers k such that (19*10^k + 737)/9 is prime.at n=16A293536
• Numbers k such that Bernoulli number B_{k} has denominator 13530.at n=11A295587
• Number of prefix normal palindromes of length n.at n=35A308465
• Indices of primes followed by a gap (distance to next larger prime) of 44.at n=14A320720
• a(n) is the number of odd-balanced unimodal sequences of weight 2n+2.at n=22A335768
• Number of integer partitions with sum <= n whose distinct parts can be linearly combined using nonnegative coefficients to obtain n.at n=28A365379