A061361 a(1) = 4; a(n) = least number such that the concatenation a(n)a(n-1)...a(2)a(1) is a square.

4, 6, 17, 604, 9612, 85848855, 109457393440691436, 16484027824615378535694780556419522, 2537811713051483817817710620248313487995814710180147690293469081793581

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Example

a(3)a(2)a(1) = 1764 = 42^2, a(4)a(3)a(2)a(1) = 6041764 = 2458^2, a(5)a(4)a(3)a(2)a(1) = 8584885596126041764 = 2929997542^2.

Crossrefs

Cf. A050636, A050637, A061359, A061363.

Sequence in context: A270270 A211949 A079803 * A332986 A113610 A309334

Adjacent sequences: A061358 A061359 A061360 * A061362 A061363 A061364

Keyword

nonn,base

Author

Amarnath Murthy, Apr 28 2001

Extensions

Corrected by Larry Reeves (larryr(AT)acm.org), May 07 2001

More terms from Ulrich Schimke (ulrschimke(AT)aol.com), Nov 06 2001

Status

approved