experimental-projects/oeis-research/Patrick De Geest/a(n)-th prime has exactly n zeros/prog.sf

#!/usr/bin/ruby

# a(n)-th prime is the smallest prime containing exactly n 0's.
# https://oeis.org/A037052

var h = Hash(
   0  2
   1  101
   2  1009
   3  10007
   4  100003
   5  1000003
   6  20000003
   7  100000007
   8  1000000007
   9  30000000001
  10  100000000003
  11  2000000000003
  12  40000000000001
  13  1000000000000037
  14  6000000000000001
  15  20000000000000003
  16  100000000000000003
  17  1000000000000000003
  18  60000000000000000007
  19  500000000000000000003
  20  8000000000000000000009
  21  10000000000000000000009
  22  1000000000000000000000049
  23  1000000000000000000000007
)

for v in (h.values.sort) {
    if (v.to_s =~ /^1/) {
        say [v, primepi(10**v.ilog10) + primepi(10**v.ilog10, v)]
    }
    else {
        say [v, primepi(v)]
    }
}

__END__
[2, 1]
[101, 26]
[1009, 169]
[10007, 1230]
[100003, 9593]
[1000003, 78499]
[20000003, 1270608]
[100000007, 5761456]
[1000000007, 50847535]
[30000000001, 1300005927]
[100000000003, 4118054814]
[2000000000003, 73301896140]
[40000000000001, 1320811971703]
[1000000000000037, 29844570422670]
[6000000000000001, 169969662554552]
[20000000000000003, 547863431950009]
[100000000000000003, 2623557157654234]
[1000000000000000003, 24739954287740861]

1, 26, 169, 1230, 9593, 78499, 1270608, 5761456, 50847535, 1300005927, 4118054814, 73301896140, 1320811971703, 29844570422670, 169969662554552, 547863431950009, 2623557157654234, 24739954287740861