A062096 a(1) = 2; for n > 1, a(n) is smallest number, greater than a(n-1), which is relatively prime to the sum of all previous terms.

2, 3, 4, 5, 9, 10, 13, 15, 16, 17, 19, 20, 22, 23, 25, 26, 27, 29, 31, 33, 34, 35, 37, 38, 39, 41, 43, 45, 46, 47, 49, 50, 51, 53, 56, 57, 59, 60, 61, 63, 64, 65, 67, 68, 69, 71, 72, 73, 75, 76, 79, 81, 83, 85, 86, 88, 89, 95, 96, 97, 101, 102, 103, 107, 108, 109, 113, 114

Offset

1,1

Links

Table of n, a(n) for n=1..68.

Example

After 5 the next term is 9 as 2 + 3 + 4 + 5 = 14 and 6, 7 and 8 have common divisors with 14.

Maple

a[1]:=2: for m from 2 to 80 do b:=proc(n) if gcd(sum(a[j], j=1..m-1), n)=1 then n else fi end: M:=[seq(b(n), n=a[m-1]+1..200)]: a[m]:=M[1] od:seq(a[n], n=1..80); # Emeric Deutsch, Jul 18 2005

Prog

(PARI) first(n) = my(v = vector(n), s, t); s = v[1] = 2; for(i = 2, n, t=v[i-1]+1; while(gcd(t, s)!=1, t++); v[i]=t; s+=v[i])); v \\ David A. Corneth, Aug 11 2017

Crossrefs

Sequence in context: A015837 A262511 A075177 * A360687 A176008 A143827

Adjacent sequences: A062093 A062094 A062095 * A062097 A062098 A062099

Keyword

nonn,easy

Author

Amarnath Murthy, Jun 19 2001

Extensions

Corrected and extended by Emeric Deutsch, Jul 18 2005

Status

approved