OFFSET

1,1

COMMENTS

EXAMPLE

a(1) = 4 because 4 (base 8) = 4 (base 10) = 2 * 2, a semiprime (A001358).

a(2) = 6 because 6 (base 8) = 6 (base 10) = 2 * 3.

a(3) = 8 because 8 (base 8) = 10 and 10 (base 10) = 2 * 5.

a(4) = 12 because 12 (base 8) = 14 and 14 (base 10) = 2 * 7.

a(5) = 13 because 13 (base 8) = 15 and 15 (base 10) = 3 * 5.

MATHEMATICA

Select[Range[195], Plus @@ Last /@ FactorInteger[FromDigits[IntegerDigits[ #, 8]]] == 2 &] (* Ray Chandler, Aug 05 2005 *)

CROSSREFS

KEYWORD

base,easy,nonn

AUTHOR

Jonathan Vos Post, Jul 30 2005

EXTENSIONS

Extended by Ray Chandler, Aug 05 2005

STATUS

approved