

A157908


Nonprimes whose digits are all square.


2



0, 1, 4, 9, 10, 14, 40, 44, 49, 90, 91, 94, 99, 100, 104, 110, 111, 114, 119, 140, 141, 144, 190, 194, 400, 404, 410, 411, 414, 440, 441, 444, 490, 494, 900, 901, 904, 909, 910, 914, 940, 944, 949, 990, 994, 999, 1000, 1001, 1004, 1010, 1011, 1014, 1040, 1041
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OFFSET

1,3


COMMENTS

Square digits are 0, 1, 4 or 9.


LINKS



FORMULA

a(n) = Theta(n^(log_4 10))


MATHEMATICA

Select[FromDigits/@Tuples[{0, 1, 4, 9}, 4], !PrimeQ[#]&] (* Harvey P. Dale, Oct 14 2014 *)


CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



