|
|
A130816
|
|
a(1) = 2, a(2) = 2, a(3) = 1, a(n) = a(n-3) + floor(a(n-2)/2) for n >= 4.
|
|
1
|
|
|
2, 2, 1, 3, 2, 2, 4, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 14, 17, 19, 22, 26, 30, 35, 41, 47, 55, 64, 74, 87, 101, 117, 137, 159, 185, 216, 251, 293, 341, 397, 463, 539, 628, 732, 853, 994, 1158, 1350, 1573, 1833, 2136, 2489, 2901, 3380, 3939, 4591, 5349, 6234, 7265, 8466
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Resulted from a search for a suitable slowly increasing, not easily predictable but not random integer sequence for testing hard drive storage patterns.
|
|
LINKS
|
|
|
EXAMPLE
|
a(1) = 2, a(2) = 2, a(3) = 1, a(4) = 2 + floor(2/2) = 3, a(5) = 2 + floor(1/2) = 2.
|
|
MAPLE
|
a:= proc(n) a(n):=`if`(n<4, [2$2, 1][n], iquo(a(n-2), 2)+a(n-3)) end:
|
|
MATHEMATICA
|
RecurrenceTable[{a[n] == a[n-3] + Floor[a[n-2]/2], a[1] == 2, a[2] == 2, a[3] == 1}, a, {n, 1, 70}] (* Georg Fischer, May 05 2021 *)
|
|
PROG
|
(C) int f1 = 2; int f2 = 2; int f3 = 1; int next_seq() { int f = f1 + f2/2; f1 = f2; f2 = f3; f3 = f; return f; }
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Ivan Voras (ivoras(AT)gmail.com), Jul 16 2007
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|