A182559 a(n) = a(n-2)*2 + floor(sqrt(a(n-1))).

0, 1, 1, 3, 3, 7, 8, 16, 20, 36, 46, 78, 100, 166, 212, 346, 442, 713, 910, 1456, 1858, 2955, 3770, 5971, 7617, 12029, 15343, 24181, 30841, 48537, 61902, 97322, 124115, 194996, 248671, 390490, 497966, 781685, 996816, 1564368, 1994882, 3130148, 3991533, 6262293

Offset

0,4

Links

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

Formula

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

Mathematica

RecurrenceTable[{a[0]==0, a[1]==1, a[n]==2a[n-2]+Floor[Sqrt[a[n-1]]]}, a, {n, 50}] (* Harvey P. Dale, Jul 25 2019 *)

Prog

(Python)
import math
prpr = 0
prev = 1
for n in range(55):
    current = prpr*2 + int(math.sqrt(prev))
    print(prpr, end=', ')
    prpr = prev
    prev = current

Crossrefs

Cf. A076677, A076678, A182557.

Sequence in context: A320291 A320294 A304179 * A108046 A286110 A116157

Adjacent sequences: A182556 A182557 A182558 * A182560 A182561 A182562

Keyword

nonn

Author

Alex Ratushnyak, May 05 2012

Status

approved