|
| |
|
|
A139542
|
|
a(n) = a(n-1) + largest divisor of a(n-1) <= sqrt(a(n-1)).
|
|
1
| |
|
|
1, 2, 3, 4, 6, 8, 10, 12, 15, 18, 21, 24, 28, 32, 36, 42, 48, 54, 60, 66, 72, 80, 88, 96, 104, 112, 120, 130, 140, 150, 160, 170, 180, 192, 204, 216, 228, 240, 255, 270, 285, 300, 315, 330, 345, 360, 378, 396, 414, 432, 450, 468, 486, 504, 525, 546, 567, 588, 609
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
LINKS
| Harvey P. Dale, Table of n, a(n) for n = 1..1000
|
|
|
EXAMPLE
| Term after 36 is 42 because largest divisor of 36 <= sqrt(36) is 6 and 36+6=42
|
|
|
MATHEMATICA
| a = {1}; Do[AppendTo[a, a[[ -1]] + Max[Select[Divisors[a[[ -1]]], # <= Sqrt[a[[ -1]]] &]]], {60}]; a [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 28 2008]
ld[n_]:=Max[Select[Divisors[n], #<=Sqrt[n]&]]; NestList[#+ld[#]&, 1, 60] (* From Harvey P. Dale, Nov 26 2011 *)
|
|
|
CROSSREFS
| Sequence in context: A130519 A001972 A005705 * A093717 A002093 A179971
Adjacent sequences: A139539 A139540 A139541 * A139543 A139544 A139545
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| J. Lowell (jhbubby(AT)mindspring.com), Jun 10 2008
|
|
|
EXTENSIONS
| More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 28 2008
|
| |
|
|
