OFFSET
1,2
EXAMPLE
10 --> 1^2+0^2 = 1+0 =1
13 --> 1^2+3^2 = 1+9 = 10
23 --> 2^2+3^2 = 4+9 =13
1233 --> 1^2+2^2+3^3+3^2 = 1+4+9+9 = 23
33999999999999999 = 3^2*2 + 9^2*15 = 1233
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava and Giorgio Balzarotti, Mar 20 2007; corrected Mar 23 2007
EXTENSIONS
Next term is greater than 10^419753086419753. [From Charles R Greathouse IV, Nov 13 2010]
STATUS
approved