A119992 a(n) = n-th positive integer which is coprime to n!.

1, 3, 7, 11, 17, 19, 29, 31, 37, 41, 47, 53, 61, 67, 71, 73, 83, 89, 101, 103, 107, 109, 127, 131, 137, 139, 149, 151, 163, 167, 179, 181, 191, 193, 197, 199, 223, 227, 229, 233, 241, 251, 263, 269, 271, 277, 283, 293, 307, 311, 313, 317, 337, 347, 349, 353, 359

Offset

1,2

Comments

Primes not in a(n): {2, 5, 13, 23, 43, 59, 79, 97, 113, 157, 173, 211, 239, 257, 281, 331, 373, 389, 433, 461, 479, 523, 569, 607, 659, ...} - Michael De Vlieger, Oct 02 2017

Links

Michael De Vlieger, Table of n, a(n) for n = 1..1000

Example

1,5,7,11,13,17,19,23,25,...is the sequence of positive integers which are coprime to 4! = 24. 11 is the 4th such integer, so a(4) = 11.

Maple

A119992 := proc(n)
    local i, j ;
    j := 0 ;
    i := 1 ;
    while true do
        if gcd(i, n!) = 1 then
            j := j+1 ;
            if j = n then
                return i ;
            break ;
            fi ;
        fi ;
        i := i+1 ;
    od ;
end:
seq(A119992(n), n=1..100) ; # R. J. Mathar, Dec 22 2013

Mathematica

With[{nn = 57}, Table[Select[{1}~Join~Prime@ Range[2 nn], CoprimeQ[n!, #] &][[n]], {n, nn}]] (* Michael De Vlieger, Oct 02 2017 *)

Crossrefs

Cf. A000142.

Sequence in context: A156284 A045419 A049098 * A023249 A249682 A090513

Adjacent sequences: A119989 A119990 A119991 * A119993 A119994 A119995

Keyword

nonn

Author

Leroy Quet, Aug 03 2006

Extensions

More terms from R. J. Mathar, Aug 06 2006

Status

approved