49591domain: NAppears in sequencesNumber of (binary) bit strings of length n in which no even block of 0's is followed by an odd block of 1's.at n=17A065455a(n) = A186434(n)/4.at n=18A271908Semiprimes k = pq such that p^k == p (mod k) and q^k == q (mod k).at n=34A294169Numbers k such that 461*2^k+1 is prime.at n=8A323200