A095252 a(n) = floor(sqrt{concatenation n,(n-1),...,3,2,1}).

1, 4, 17, 65, 233, 808, 2766, 9362, 31426, 104822, 1054033, 11005043, 114547418, 1188747707, 12305003905, 127088210000, 1310019623181, 13480213329659, 138498072735374, 1420979139942389, 14560878466498901, 149036972532711329, 1523880579042109897

Offset: 1

Author

Amarnath Murthy, Jun 17 2004

Keywords

• base
• easy
• nonn
• less

Comments

a(n) = floor(sqrt(A000422(n))). - Stefan Steinerberger, May 05 2007

Examples

			a(4) = floor(sqrt(4321)) = 65.
		

Crossrefs

Cf. A068995.

Programs

Maple

a:= n-> floor(sqrt(parse(cat((n-i)$i=0..n-1)))):
seq(a(n), n=1..30);  # Alois P. Heinz, Aug 26 2015

Mathematica

Table[Floor[Sqrt[FromDigits[Flatten[Table[IntegerDigits[i],{i,n,1,-1}]]]]],{n,1,25}] (* Stefan Steinerberger, May 05 2007 *)
Table[Floor[Sqrt[FromDigits[Flatten[IntegerDigits/@Range[n,1,-1]]]]],{n,25}] (* Harvey P. Dale, Jul 22 2024 *)

Extensions

More terms from Stefan Steinerberger, May 05 2007