51279480

Appears in sequences

• a(n) = 14*(n+1)*binomial(n+4,8).at n=13A027804
• Indices k of hex numbers H(k) that are also triangular.at n=8A087125
• Number of (n+2) X 9 binary arrays avoiding patterns 001 and 101 in rows and columns.at n=11A202201
• a(1) = least k such that 1/1+1/2+1/3+1/4+1/5 < H(k) - H(5); a(2) = least k such that H(a(1)) - H(5) < H(k) -H(a(1)), and for n > 2, a(n) = least k such that H(a(n-1)) - H(a(n-2)) > H(k) - H(a(n-1)), where H = harmonic number.at n=6A228016