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A125028
a(1)=2, a(n)=2*a(n-1)-floor(sqrt(a(n-1))).
0
2, 3, 5, 8, 14, 25, 45, 84, 159, 306, 595, 1166, 2298, 4549, 9031, 17967, 35800, 71411, 142555, 284733, 568933, 1137112, 2273158, 4544809, 9087487, 18171960, 36339658, 72673288, 145338052, 290664049, 581311050
OFFSET
1,1
COMMENTS
For any a(1)>1, a(n)/a(n-1)=>2; for large n's, a(n)=>c*2^n with c depending on a(1)>1; for a(1)=2 c=0.270675.
MATHEMATICA
NestList[2#-Floor[Sqrt[ # ]]&, 2, 30]
CROSSREFS
Sequence in context: A128021 A036241 A192633 * A349777 A119262 A177510
KEYWORD
nonn
AUTHOR
Zak Seidov, Nov 16 2006
STATUS
approved