A048884 - OEIS

A048884

Numbers k such that sigma(k) - k = k - pi(k) - 1 where pi(k) is A000720.

1, 5, 9, 26, 236, 244, 4862, 5396, 6868, 9608, 9704, 23764, 82665, 733064, 25881904, 25886864, 33299110, 261851668

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

a(19) > 3*10^12. - Giovanni Resta, Mar 31 2017

LINKS

MATHEMATICA

For[i = 1, i < 10^9, i++, If[DivisorSigma[1, i] - i == i - PrimePi[i] - 1, Print[i]]; ]; (* Sam Handler (sam_5_5_5_0(AT)yahoo.com), Aug 29 2006 *)

CROSSREFS

KEYWORD

more,nonn,hard

AUTHOR

EXTENSIONS

More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Aug 29 2006

STATUS

approved