|
%I #17 Apr 08 2020 00:13:13
%S 97402668820327149658203125,81209257154451887573232591061530625,
%T 13375863052949754169544537548117223100875,
%U 4587921027161765680153776379004207523600125,2478309849684200670569842256516437530517578125
%N Numbers of the form 5^r*7^s whose decimal representations are such that each digit 0-9 appears a prime number of times.
%C See the formula section for more data, and other sequences in cross-reference for motivation and similar sequences.
%F A217425(n) = 5^A217426(n) * 7^A217427(n).
%e A217426(1)=13 and A217427(1)=20, so this sequence's first term is 5^13 * 7^20. It has two copies each of the digits 1, 3, 4, 5, 7 and 9; three each of 0's, 6's and 8's; and five 2's.
%Y Cf. A217854, A217426, A217427, A217404, A217407, A217410, A217413, A217416, A217419, A217422, A217428, A217431.
%K nonn,base,less
%O 1,1
%A _James G. Merickel_, Oct 05 2012
|
