1629219

Appears in sequences

• Composite numbers n such that n+2 is also composite and such that (sopfr(n), sopfr(n+2)) is a twin prime pair. A001414 explains notation 'sopfr(n)'.at n=18A247048
• a(n) = Sum_{k=1..n} floor((n/k)^k).at n=32A347415