21718

Appears in sequences

• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 100 ones.at n=10A031868
• Decimal part of cube root of n starts with 9: first term of runs.at n=26A034135
• Volume of Johnson square pyramid placed upright on cube (rounded down) with edge lengths equal to n.at n=25A227221
• Number of self-avoiding walks on the truncated square tiling with n steps.at n=15A249565
• Irregular triangle read by rows: T(n,k) is the number of n X n tic-tac-toe positions (up to rotation and reflection) with k tokens (i.e., after k plays) which allow a winning strategy for O (n > 0, 0 <= k <= n^2).at n=29A317574