A159021 a(0)=19; a(n) = a(n-1) + floor(sqrt(a(n-1))), n > 0.

19, 23, 27, 32, 37, 43, 49, 56, 63, 70, 78, 86, 95, 104, 114, 124, 135, 146, 158, 170, 183, 196, 210, 224, 238, 253, 268, 284, 300, 317, 334, 352, 370, 389, 408, 428, 448, 469, 490, 512, 534, 557, 580, 604, 628, 653, 678, 704, 730, 757, 784, 812, 840, 868, 897, 926, 956, 986, 1017

Offset

0,1

Comments

Row 3 in square array A159016.

This sequence contains infinitely many squares. - Philippe Deléham, Apr 04 2009

Conjecture: The squares are of the form (7*2^k)^2 (see A005009). - Vincenzo Librandi, Apr 10 2009

Links

Harvey P. Dale, Table of n, a(n) for n = 0..1000

Mathematica

NestList[#+Floor[Sqrt[#]]&, 19, 60] (* Harvey P. Dale, Jan 04 2013 *)

Crossrefs

Cf. A028392, A005009.

Sequence in context: A317254 A226687 A070299 * A100460 A166061 A224534

Adjacent sequences: A159018 A159019 A159020 * A159022 A159023 A159024

Keyword

nonn

Author

Philippe Deléham, Apr 02 2009

Extensions

More terms from Vincenzo Librandi, Apr 10 2009

Status

approved