81840

Appears in sequences

• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 13.at n=24A031691
• a(n) = 2*binomial(n,4).at n=33A034827
• a(n) = binomial(2*n, n) mod ((n+1)*(n+2)*(n+3)*(n+4)).at n=28A065346
• a(n) = 169*n^2 + 2*n.at n=21A158220
• Number of reduced words of length n in Coxeter group on 5 generators S_i with relations (S_i)^2 = (S_i S_j)^7 = I.at n=8A164354
• Numbers with prime factorization p*q*r*s*t^4 (where p, q, r, s, t are distinct primes).at n=27A190110
• Number of Sidon subsets of {1,...,n} of size 4.at n=40A241688
• Number of non-equivalent ways to tile an n X n X n triangular area with two 2 X 2 X 2 triangular tiles and an appropriate number (= n^2-8) of 1 X 1 X 1 tiles.at n=30A286444
• Number of nX3 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=11A302146
• a(n) = n*(n + 1)*(16*n - 1)/6.at n=31A304659
• a(n) = A351477(n) * FA where F is the Fermat point of a primitive integer-sided triangle ABC with A < B < C < 2*Pi/3 and FA + FB + FC = A336329(n).at n=15A351801