prog.sf

#!/usr/bin/ruby

# Least Lucas number with n Lucas divisors
# https://oeis.org/A356123

# Known terms:
#   1, 2, 4, 18, 1364, 1860498, 2537720636, 6440026026380244498, 8784200221406821330636, 77162173529763648886126034136172445632164498

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

var table = Hash()

for k in (1..1e6) {

    var t = divisors(k.lucas).count{.is_lucas}

    if (!table.has(t)) {
        table{t} = k
        say("a(#{t}) = #{k.lucas}")
    }
}

__END__
a(1) = 1
a(2) = 3
a(3) = 4
a(4) = 18
a(5) = 1364
a(6) = 1860498
a(7) = 2537720636
a(8) = 6440026026380244498
a(9) = 8784200221406821330636
a(10) = 77162173529763648886126034136172445632164498
a(13) = 677807981804381412733419097483256033462649109976189806684020291364
a(11) = 4365101043708483494615466932242949707161871659736799144058331102381689400753867700636