login
A262231
First term is 2; each subsequent term is the least number greater than the previous term but not a multiple of the successor of any previous term.
1
2, 4, 7, 11, 13, 17, 19, 22, 26, 29, 31, 34, 37, 41, 43, 47, 49, 52, 58, 61, 67, 71, 73, 77, 79, 82, 86, 89, 91, 94, 97, 101, 103, 107, 109, 113, 116, 119, 121, 127, 131, 133, 137, 139, 142, 146, 149, 151, 157, 163, 167, 169, 172, 178, 181, 187, 191
OFFSET
1,1
COMMENTS
If the twin prime conjecture is true, this sequence has infinitely many pairs of terms with difference at most 3.
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A100464(n) - 1.
EXAMPLE
25 is excluded because it is a multiple of 4+1; 26 is not a multiple of 3,5,8,...,23 so it remains in the sequence.
PROG
(PARI) has(n)=fordiv(n, d, if(mapisdefined(m, d-1), return(0))); 1
first(n)=local(m=Map(Mat([2, 0]))); my(t=3); while(#m<n, while(!has(t++), ); mapput(m, t, 0)); Mat(m)[, 1]~ \\ Charles R Greathouse IV, Sep 16 2015
CROSSREFS
Cf. A100464.
Sequence in context: A087285 A107791 A181518 * A356133 A191323 A307207
KEYWORD
nonn
AUTHOR
Drake Thomas, Sep 15 2015
STATUS
approved