OFFSET
4,1
COMMENTS
This sequence is an analog of sequence A001273 with the unhappy numbers instead of the happy numbers.
LINKS
W. Schneider, Unhappy Numbers.
EXAMPLE
15 is the fourth term because: 15: 1^2 + 5^2 = 26 / 26: 2^2 + 6^2 = 40 / 40: 4^2 + 0^2 = 16 and 16 is a member of the unhappy number series (4, 16, 37, 58, 89, 145, 42, 20)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Sergio Pimentel, Apr 30 2004
EXTENSIONS
The next term, 577999999999....999999999999 (199 digits) is too large to include.
Edited by Charles R Greathouse IV, Aug 03 2010
STATUS
approved