0,1

If n =3p and n+1 = 2q where p and q are primes then n is a member.

Table of n, a(n) for n=0..47.

9 is a member as psigma(9) = 1+3 +9 = psigma(10) = 1+2 +10 = 13.

Cf. A086469.

Sequence in context: A110701 A243703 A133929 * A176256 A017629 A216240

Adjacent sequences: A086467 A086468 A086469 * A086471 A086472 A086473

nonn

Amarnath Murthy, Jul 21 2003

Corrected and extended by David Wasserman, Mar 07 2005

approved