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 A247900 First differences of A247681 1
 54, 54, 36, 54, 72, 18, 18, 36, 36, 18, 18, 54, 36, 18, 36, 54, 36, 54, 18, 18, 18, 18, 54, 18, 54, 18, 36, 54, 18, 54, 18, 36, 18, 36, 54, 18, 18, 18, 18, 54, 18, 18, 18, 18, 18, 36, 36, 18, 18, 72, 18, 36, 36, 36, 18, 36, 54, 18, 18, 36, 18, 18, 18, 18, 18, 54, 36, 36, 18, 72, 18, 18, 72, 18, 36, 36, 18, 18, 18, 36, 90 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms have digital root equal to 9. LINKS Odimar Fabeny, Table of n, a(n) for n = 1..10000 MATHEMATICA Join[{54}, Differences[Select[Range[1, 3500, 18], !PrimeQ[#]&]]] (* Harvey P. Dale, Apr 25 2018 *) CROSSREFS Cf. A247681. Sequence in context: A033374 A247897 A116386 * A107936 A252722 A326181 Adjacent sequences:  A247897 A247898 A247899 * A247901 A247902 A247903 KEYWORD nonn,easy AUTHOR Odimar Fabeny, Sep 26 2014 STATUS approved

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Last modified December 15 00:30 EST 2019. Contains 329988 sequences. (Running on oeis4.)