OFFSET
1,1
COMMENTS
Number of terms less than 10^n: 1, 3, 8, 22, 48, 103, 230, 611, ...; number of odd terms less than 10^n: 0, 1, 6, 12, 21, 51, 120, 331, ..., . - Robert G. Wilson v, Dec 12 2006
EXAMPLE
Prime factors of 76 are 2 and 19; twice their sum is 42 which the product of 7 and 6 - the digits of 76.
MATHEMATICA
Select[Range[2, 20000], Times @@ IntegerDigits[ # ] == 2 Plus @@ Transpose[FactorInteger[ # ]][[1]] &]
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Tanya Khovanova, Dec 10 2006
EXTENSIONS
More terms from Robert G. Wilson v, Dec 12 2006
STATUS
approved