OFFSET
1,1
COMMENTS
a(1)=2205=A109510(29), a(2)-a(8) from Max Alekseyev.
sqrt(sigma(a(n))-2*a(n)): 6, 3432, 8250, 11022, 19376.
PROG
(PARI) is(n)=n%2&&issquare(sigma(n)-2*n) \\ Charles R Greathouse IV, Dec 06 2011
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 15 2010
EXTENSIONS
a(6)-a(18) from Donovan Johnson, Oct 17 2010
a(19)-a(20) from Donovan Johnson, Dec 06 2011
STATUS
approved