21250

Appears in sequences

• Expansion of bracket function.at n=13A000750
• Numbers k such that k | 13^k + 1.at n=29A015963
• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite FER = Ferrierite Na2Mg2[Al6Si30O72].18H2O starting with a T1 atom.at n=13A019130
• Numbers that are the sum of 2 nonzero squares in exactly 5 ways.at n=6A025288
• Numbers that are the sum of 2 nonzero squares in 5 or more ways.at n=20A025296
• Numbers that are the sum of 2 distinct nonzero squares in exactly 5 ways.at n=4A025306
• Numbers that are the sum of 2 distinct nonzero squares in 5 or more ways.at n=18A025315
• Numbers k such that n | sigma_10(k) + phi(k)^10.at n=14A055704
• Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n.at n=42A057250
• Numbers k that can be expressed as k = w + x = y*z with w*x = y^3 + z^3 where w, x, y, and z are all positive integers.at n=33A057372
• Numbers m such that phi(m) = tau(m)^3.at n=15A068559
• Numbers k such that S(k)=d(k), where S(k) is the Kempner function (A002034) and d(k) is the number of divisors of k (A000005).at n=19A073307
• Numbers n such that number of divisors of n divides S(n), the Kempner function A002034.at n=30A073413
• Number of polyhexes with n cells that tile the plane isohedrally but not by translation or by 180-degree rotation (Conway criterion).at n=11A075213
• Second binomial transform of F(n+1).at n=8A081567
• Square array of binomial transforms of Fibonacci numbers, read by ascending antidiagonals.at n=63A081572
• For k >= 1, let b(k) = ceiling( Sum_{i=1..k} 1/i ); a(n) = number of b(k) that are equal to n.at n=11A096005
• Numbers that reach the fixed point 89 under iteration of f(x) = reverse(x) - maxdigit(x).at n=26A097155
• A Chebyshev transform of the Padovan numbers.at n=36A100049
• Sum of the sizes of the tails below the Durfee squares of all partitions of n.at n=25A116365