131882

Appears in sequences

• Numbers k such that sigma(phi(k)) = sigma(k) where sigma is the sum of divisors function A000203 and phi is the Euler totient function A000010.at n=24A033631
• 1/4 the number of (n+1) X 7 binary arrays with all 2 X 2 subblock sums the same.at n=17A183983
• a(n) = Sum_{k=1..n} 2^(n mod k).at n=32A198383
• Numbers n such that n^32+1 and (n+2)^32+1 are both prime.at n=35A217992