A121047 a(0) = a(1) = 1; for n >= 2, a(n) = the n-th integer from among those positive integers which are coprime to a(n-1)+a(n-2).

1, 1, 3, 5, 7, 13, 13, 15, 17, 17, 21, 23, 25, 37, 27, 29, 37, 53, 67, 71, 61, 67, 43, 61, 51, 57, 77, 53, 73, 101, 91, 91, 81, 67, 69, 73, 73, 75, 77, 81, 81, 121, 83, 137, 119, 89, 99, 95, 95, 127, 151, 101, 181, 161, 169, 227, 181, 179, 217, 193, 153, 121, 123, 127, 159

Offset

0,3

Links

Table of n, a(n) for n=0..64.

Example

a(6)+a(7) = 28. 1,3,5,9,11,13,15,17,19,... is the sequence of positive integers which are coprime to 28. 17 is the 8th of these integers, so a(8) = 17.

Prog

(PARI) {m=64; print1(c=1, ", ", b=1, ", "); for(n=2, m, k=n; s=c+b; a=0; while(k>0, a++; if(gcd(s, a)==1, k--)); print1(a, ", "); c=b; b=a)} - (Klaus Brockhaus, Aug 09 2006)

Crossrefs

Sequence in context: A143245 A018205 A370762 * A152075 A092789 A092793

Adjacent sequences: A121044 A121045 A121046 * A121048 A121049 A121050

Keyword

nonn

Author

Leroy Quet, Aug 08 2006

Extensions

More terms from Klaus Brockhaus, Aug 09 2006

Status

approved