A167041 Squares that remain squares when prefixed with a 6.

4, 25, 400, 2500, 40000, 250000, 2805625, 4000000, 25000000, 36300625, 43890625, 221265625, 280562500, 400000000, 2500000000, 3630062500, 4389062500, 22126562500, 28056250000, 40000000000, 250000000000, 363006250000, 438906250000, 2212656250000, 2805625000000

Offset

1,1

Comments

Numbers s of A000290 such that 6*10^A055642(s)+s is also in A000290.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..1000

Example

4 = 2^2 is a square, and if prefixed with 6 becomes the square 64 = 8^2.

Crossrefs

Sequence in context: A308476 A222902 A086216 * A123129 A075577 A004019

Adjacent sequences: A167038 A167039 A167040 * A167042 A167043 A167044

Keyword

nonn,base

Author

Claudio Meller, Oct 27 2009

Extensions

Keyword:base added by R. J. Mathar, Oct 28 2009

More terms from Chai Wah Wu, Sep 11 2014

Status

approved