A115551 Numbers k such that the concatenation of 8*k with k gives a square.

1, 4, 9, 89, 889, 8889, 88889, 888889, 8888889, 88888889, 888888889, 1026765584, 1066636289, 1107266436, 1148656025, 1190805056, 1233713529, 1277381444, 1321808801, 1366995600, 1412941841, 1459647524, 1507112649, 1555337216

Offset

1,2

Links

Table of n, a(n) for n=1..24.

Example

8_1 = 9^2.

Crossrefs

Cf. A102567, A106497, A115527 - A115556.

Sequence in context: A248245 A368629 A077530 * A227419 A242097 A220972

Adjacent sequences: A115548 A115549 A115550 * A115552 A115553 A115554

Keyword

nonn,base

Author

Giovanni Resta, Jan 25 2006

Status

approved