OFFSET
1,2
LINKS
P. De Geest, World!Of Numbers
FORMULA
EXAMPLE
a(n)=77 so 1+2+3+4+5+6+7+8+9+11+22+33+44+55+66+77 = 353.
CROSSREFS
KEYWORD
nonn,hard,base
AUTHOR
Patrick De Geest, Sep 15 1998
EXTENSIONS
Offset changed to 1 by R. J. Mathar, Sep 09 2015
STATUS
approved