OFFSET
1,1
FORMULA
a(n) = 6*prime(n) for n>=4. - Jose Brox (tautocrona(AT)terra.es), Mar 24 2003
EXAMPLE
The first eight abundant numbers are 12, 18, 20, 24, 30, 36, 40 and 42. But only the last one is divisible by 7, the fourth prime number. Therefore a(4) = 42.
MATHEMATICA
If[n==2||n==3, 4, 6]Prime[n]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert G. Wilson v, Sep 15 2001
STATUS
approved