OFFSET
1,2
COMMENTS
Lim_{n->infinity} a(n)/(2^n) = 1.34669079829214755988545564864530863502076381405786.... - Jon E. Schoenfield, Oct 04 2013
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..1000
FORMULA
Lim_{n->infinity} a(n+1)/a(n) = 2. - Zak Seidov, May 03 2009
EXAMPLE
a(5) = 36 because it is the smallest square greater than the sum of a(1)..a(4) = 30.
MAPLE
a[1] := 1:a[2] := 4:for n from 3 to 45 do a[n] := ceil(evalf(sqrt(sum(a[i], i=1..n-1)+1/10^19), 100))^2; od:seq(a[k], k=1..45);
MATHEMATICA
nxt[{p_, a_}]:=Module[{k=1}, While[!IntegerQ[Sqrt[p+k]], k++]; {2p+k, p+k}]; NestList[nxt, {1, 1}, 30][[All, 2]] (* Harvey P. Dale, May 30 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Oct 21 2002
EXTENSIONS
Corrected and extended by Sascha Kurz, Jan 22 2003
STATUS
approved