A242078 Smallest square number > 10*a(n-1) with a(1) = 1.

1, 16, 169, 1764, 17689, 177241, 1774224, 17749369, 177502329, 1775105424, 17751298756, 177513070329, 1775132540281, 17751332312289, 177513333968569, 1775133399758224, 17751334196261689, 177513342503762329

Offset

1,2

Links

Jon E. Schoenfield, Table of n, a(n) for n = 1..250

Example

Term after 169 cannot be 1681 because 1681 is less than 10 times 169.

Mathematica

NestList[Ceiling[Sqrt[10#]]^2&, 1, 20] (* Harvey P. Dale, Sep 03 2020 *)

Prog

(PARI) lista(nn, k=10) = {a=1; for (n=1, nn, print1(a, ", "); a = (sqrtint(a*k)+1)^2; ); } \\ Michel Marcus, May 06 2014
(Magma) nMax:=100; a:=1; for n in [1..nMax] do a:=(Isqrt(a*10)+1)^2; a; end for; // Jon E. Schoenfield, May 06 2014

Crossrefs

Cf. other sequences with smallest square > k*a(n-1): A175627 (k=2), A060867 (k=4).

Sequence in context: A067711 A068175 A238976 * A264092 A050628 A048557

Adjacent sequences: A242075 A242076 A242077 * A242079 A242080 A242081

Keyword

nonn

Author

J. Lowell, May 03 2014

Status

approved