1,1

http://www.primepuzzles.net/puzzles/puzz_203.htm Corresponding -1+perfect primes are called at this web-site left-perfect-primes and the single term found is 5.

a(n)=-1+A07621[n];

Cf. A061644, A094468.

Sequence in context: A115738 A115763 A052000 this_sequence A091511 A067483 A102638

Adjacent sequences: A094464 A094465 A094466 this_sequence A094468 A094469 A094470

more,nonn

Labos E. (labos(AT)ana.sote.hu), May 12 2004