OFFSET
1,1
COMMENTS
a(24) > 2*10^12. - Donovan Johnson, Jan 16 2011
EXAMPLE
12 is in the sequence because 2 + 3 + 5 + 6 + 7 + 8 + 10 + 11 + 12 = 64 = 8*8.
PROG
(PARI) isA065992(n) = {local(m); m=floor(sqrt(n)); if(n<2, 0, issquare((n*(n+1)/2)-(m*(m+1)*(2*m+1)/6)))} \\ Michael B. Porter, Feb 02 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Ayres (jonathan.ayres(AT)ntlworld.com), Dec 10 2001
EXTENSIONS
a(20)-a(23) from Donovan Johnson, Jan 16 2011
STATUS
approved