675683

Appears in sequences

• Numbers that are the product of a pair of twin primes.at n=31A037074
• Product of twin primes of form (4*k+1,4*k+3), k>0.at n=16A071697
• Numbers that are one less than a square and have exactly 4 divisors.at n=32A134020
• Members of A159053 which are not multiples of 3.at n=19A159054
• Numbers k that form a primitive Pythagorean triple with k' and sqrt(k^2 + k'^2), where k' is the arithmetic derivative of k.at n=36A210503
• Records in A166133.at n=20A256403
• Consider numbers n such that A166133(n) sets a new record and also satisfies A166133(n)=A166133(n-1)^2-1; sequence gives values of A166133(n).at n=5A256423
• Semiprimes p*q for which p and q are successive primes and their binary representations differ from each other in one bit position only.at n=37A261080
• Numbers k such that k^2 + sopfr(k)^2 is a square, where sopfr = A001414.at n=34A386991