OFFSET
1,1
COMMENTS
Terms are the same as A054723, but in a different order.
If p is a prime and 2^p-1 is composite, each prime factor of 2^p-1 will be of the form kp+1 for some integer k. Thus, the smallest prime factor of 2^p-1 cannot be smaller than p.
The corresponding smallest prime factors are: 23, 47, 167, 223, 233, 263, 359, 383, 431, 439, 479, 503, 719, 839, 863, 887, 983, ....
EXAMPLE
83 comes before 37 because 167 (the smallest prime factor of 2^83-1) < 223 (the smallest prime factor of 2^37-1).
PROG
(PARI) lista() = {vi = readvec("b054723.txt"); vm = vector(#vi, i, 2^vi[i]-1); p = 2; nbf = 0; while ( nbf != #vm, i = 1; while (!(i>#vm) && (!vm[i] || (vm[i] % p)), i++); if (i <= #vm, print1(vi[i], ", "); vm[i] = 0; nbf ++; ); p = nextprime(p+1); ); } \\ Michel Marcus, May 14 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
J. Lowell, May 03 2014
EXTENSIONS
More terms from Michel Marcus, May 14 2014
STATUS
approved