A159018 a(0)=5; a(n) = a(n-1) + floor(sqrt(a(n-1))), n > 0.

5, 7, 9, 12, 15, 18, 22, 26, 31, 36, 42, 48, 54, 61, 68, 76, 84, 93, 102, 112, 122, 133, 144, 156, 168, 180, 193, 206, 220, 234, 249, 264, 280, 296, 313, 330, 348, 366, 385, 404, 424, 444, 465, 486, 508, 530, 553, 576, 600, 624, 648, 673, 698, 724, 750, 777, 804, 832, 860, 889, 918, 948, 978

Offset: 0

Author

Philippe Deléham, Apr 02 2009

Keywords

• nonn

Comments

Row 1 in square array A159016.

This sequence contains an infinity of squares. - Philippe Deléham, Apr 04 2009

Intersection of the sequence with A000290 generates A002063. - Vincenzo Librandi, Apr 10 2009, clarified by R. J. Mathar, Dec 03 2010

Links

• Robert Israel, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A028392.

Programs

Maple

A:= Array(0..100):
A[0]:= 5:
for n from 1 to 100 do A[n]:= A[n-1]+floor(sqrt(A[n-1])) od:
convert(A,list); # Robert Israel, Nov 26 2020