experimental-projects/oeis-research/N. J. A. Sloane/Largest prime factor of (p^p-1) over (p-1) where p = prime(n)/prog.sf

#!/usr/bin/ruby

# Largest prime factor of (p^p-1)/(p-1) where p = prime(n).
# https://oeis.org/A214812

# First few terms:
#   3, 13, 71, 4733, 1806113, 1803647, 2699538733, 109912203092239643840221, 1920647391913, 549334763, 568972471024107865287021434301977158534824481, 41903425553544839998158239, 5926187589691497537793497756719, 19825223972382274003506149120708429799166030881820329892377241, 194707033016099228267068299180244011637

include("../../../factordb/auto.sf")

func a(n) {
    var p = prime(n)
    (p**p - 1) / (p-1)
}

var bfile = File("bfile.txt").open_w.autoflush(true)

for n in (1..10000) {
    var k = a(n)
    var row = "#{n} #{gpf(k)||1}"
    say row
    bfile.say(row)
}