a(n) = smallest n-digit number with exactly n divisors, or 0 if no such number exists.
1, 11, 121, 1003, 14641, 100017, 1771561, 10000005, 100020001, 1000000016
1 seqfan posts
Sat Feb 14 17:48:59 CET 2009 [seqfan] Re: Staircase Polygons (with a Rotated Staircase hole) by perimeter