|
Search: id:A120938
|
|
|
| A120938 |
|
a(0)=1. a(n) = a(n-1) + (largest integer occurring among {a(0),a(1),a(2),..a(n-1)} which is coprime to n). |
|
+0
2
|
|
| 1, 2, 3, 5, 10, 13, 26, 52, 65, 130, 143, 273, 416, 426, 569, 1138, 1707, 3414, 3983, 7966, 11949, 13087, 26174, 38123, 76246, 152492, 190615, 381230, 571845, 1143690, 1181813, 2325503, 4651006, 9302012, 11627515, 20929527, 32557042, 65114084
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Leroy Quet, Home Page (listed in lieu of email address)
|
|
EXAMPLE
|
Among the terms {a(0),a(1),a(2),a(3),a(4),a(5)}, a(5) = 13 is the largest term which is coprime to 6. So a(6) = a(5) + 13 = 26.
|
|
MAPLE
|
A120938 := proc(nmax) local a, cpr, n, i; a := [1, 2]; for n from 3 to nmax do cpr := 0; for i from 1 to n-1 do if gcd(n-1, a[i]) = 1 and a[i] > cpr then cpr := a[i]; fi; od; a := [op(a), a[n-1]+cpr]; od: RETURN(a); end: nmax := 100 : a := A120938(nmax) : for n from 1 to nops(a) do printf("%d, ", a[n]); od; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2006
|
|
PROGRAM
|
(PARI) {m=37; print1(a=1, ", "); v=[a]; for(n=1, m, a=0; for(j=1, n, if(gcd(v[j], n)==1&&a<v[j], a=v[j])); print1(a=a+v[n], ", "); v=concat(v, a))} - (Klaus Brockhaus, Aug 16 2006)
|
|
CROSSREFS
|
Cf. A120939.
Sequence in context: A084760 A103746 A071848 this_sequence A120610 A090859 A004681
Adjacent sequences: A120935 A120936 A120937 this_sequence A120939 A120940 A120941
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Leroy Quet Jul 17 2006
|
|
EXTENSIONS
|
More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Aug 16 2006
More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 17 2006
|
|
|
Search completed in 0.002 seconds
|
