A180513 - OEIS

A180513

Lunar squares n that can be written as n = i*i in more than one way.

111111111, 111111112, 111111113, 111111114, 111111115, 111111116, 111111117, 111111118, 111111119, 111111211, 111111222, 111111223, 111111224, 111111225, 111111226, 111111227, 111111228, 111111229, 111111311, 111111322, 111111333, 111111334, 111111335, 111111336, 111111337, 111111338, 111111339, 111111411, 111111422, 111111433, 111111444, 111111445, 111111446, 111111447, 111111448, 111111449, 111111511, 111111522

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OFFSET

1,1

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 1..6561

D. Applegate, M. LeBrun and N. J. A. Sloane, Dismal Arithmetic [Note: we have now changed the name from "dismal arithmetic" to "lunar arithmetic" - the old name was too depressing]

EXAMPLE

11011*11011 = 11111*11111 = 111111111.

CROSSREFS

Cf. A087019, A181319.

Sequence in context: A158755 A293973 A094327 * A202174 A172525 A038451

Adjacent sequences: A180510 A180511 A180512 * A180514 A180515 A180516

KEYWORD

nonn

AUTHOR

David Applegate, Marc LeBrun and N. J. A. Sloane, Jan 21 2011

STATUS

approved