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A067474
Smallest n-digit square starting with 4.
2
4, 49, 400, 4096, 40000, 400689, 4000000, 40005625, 400000000, 4000056516, 40000000000, 400000591936, 4000000000000, 40000008597136, 400000000000000, 4000000100766916, 40000000000000000, 400000001222314089, 4000000000000000000, 40000000008389413041
OFFSET
1,1
FORMULA
a(n) = ceiling(sqrt(4*10^(n-1)))^2. - Rick L. Shepherd, Feb 18 2002
MATHEMATICA
nS[n_] := Module[{i = Floor[Sqrt[n]}, If[i^2==n, i^2, (i + 1)^2]]; Table[nS[4 10^i], {i, 0, 25}]
PROG
(PARI) for(n=1, 20, a=ceil(sqrt(4*10^(n-1)))^2; print(a))
CROSSREFS
Cf. A000290, A035071 (roots), A045787, A067479 (2..9).
Sequence in context: A224538 A064751 A045787 * A053769 A355481 A362479
KEYWORD
nonn,base,easy
AUTHOR
Amarnath Murthy, Feb 09 2002
EXTENSIONS
More terms from Rick L. Shepherd, Feb 18 2002
STATUS
approved