20885

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 55.at n=26A020394
• Numbers whose base-12 representation has exactly 5 runs.at n=4A043654
• Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 15.at n=24A051980
• a(n)*a(n-7) = a(n-1)a(n-6)+a(n-3)+a(n-4) with initial terms a(1)=...=a(7)=1.at n=22A133846
• G.f. y(x) is solution of x y^3 - (1 + x^2) y + 1 = 0 with y(0) = 1.at n=8A137265
• This is to A139025 as A139025 to A014688, see A139025 for details.at n=35A139026
• a(n) is the largest number in the n-th row of triangle A140997.at n=16A141018
• List of different composites in Pascal-like triangles with index of asymmetry y = 2 and index of obliquity z = 0 or z = 1.at n=36A141066
• Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 5-point zee 1,1 2,1 2,2 2,3 3,3 in any orientation.at n=15A146067
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, -1, 1), (-1, 0, 0), (1, 1, -1), (1, 1, 1)}.at n=8A149641
• Bases b for which there exists an integer y such that y^3 in base b looks like [c,d,e,c,d,e] for base-b digits c,d,e.at n=20A290185