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

Author

Amarnath Murthy, Apr 28 2001

Keywords

• nonn
• base

Examples

			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.

Extensions

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

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