A076677 a(0)=a(1)=1 a(n)=a(n-1)+floor(sqrt(a(n-2))).

1, 1, 2, 3, 4, 5, 7, 9, 11, 14, 17, 20, 24, 28, 32, 37, 42, 48, 54, 60, 67, 74, 82, 90, 99, 108, 117, 127, 137, 148, 159, 171, 183, 196, 209, 223, 237, 251, 266, 281, 297, 313, 330, 347, 365, 383, 402, 421, 441, 461, 482, 503, 524, 546, 568, 591, 614, 638, 662

Offset

0,3

Links

Table of n, a(n) for n=0..58.

Formula

a(n) is asymptotic to n^2/4

Mathematica

RecurrenceTable[{a[0]==a[1]==1, a[n]==a[n-1]+Floor[Sqrt[a[n-2]]]}, a, {n, 60}] (* Harvey P. Dale, Jul 28 2018 *)

Crossrefs

Sequence in context: A337334 A375606 A008750 * A029001 A161306 A266744

Adjacent sequences: A076674 A076675 A076676 * A076678 A076679 A076680

Keyword

nonn

Author

Benoit Cloitre, Oct 25 2002

Status

approved