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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Square digits are 0, 1, 4 or 9.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..10000

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

Cf. A000290, A141468.

Sequence in context: A243170 A054294 A198097 * A064973 A133764 A163643

Adjacent sequences:  A157905 A157906 A157907 * A157909 A157910 A157911

KEYWORD

nonn,base

AUTHOR

Juri-Stepan Gerasimov, Mar 09 2009

EXTENSIONS

Formula from Charles R Greathouse IV, Mar 25 2010

STATUS

approved

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Last modified April 22 11:46 EDT 2019. Contains 322330 sequences. (Running on oeis4.)