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A195942
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Zeroless prime powers (excluding primes): Intersection of A025475 and A052382.
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21
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1, 4, 8, 9, 16, 25, 27, 32, 49, 64, 81, 121, 125, 128, 169, 243, 256, 289, 343, 361, 512, 529, 625, 729, 841, 961, 1331, 1369, 1681, 1849, 2187, 2197, 3125, 3481, 3721, 4489, 4913, 5329, 6241, 6561, 6859, 6889, 7921, 8192
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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Reinhard Zumkeller and T. D. Noe, Table of n, a(n) for n = 1..4094 (terms < 10^10)
C. Rivera, Puzzle 607. A zeroless Prime power, on primepuzzles.net, Sept. 24, 2011.
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FORMULA
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A195942 = A025475 intersect A052382.
A010055(a(n)) * (1 - A010051(a(n))) * A168046(a(n)) = 1. - Reinhard Zumkeller, Sep 27 2011
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MATHEMATICA
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mx = 10^10; t = {1}; p = 2; While[pw = 2; While[n = p^pw; n <= mx, If[Union[IntegerDigits[n]][[1]] > 0, AppendTo[t, n]]; pw++]; pw > 2, p = NextPrime[p]]; t = Sort[t] (* T. D. Noe, Sep 27 2011 *)
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PROG
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(PARI) for( n=1, 9999, is_A025475(n) && is_A052382(n) && print1(n", "))
(Haskell)
a195942 n = a195942_list !! (n-1)
a195942_list = filter (\x -> a010051 x == 0 && a010055 x == 1) a052382_list
-- Reinhard Zumkeller, Sep 27 2011
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CROSSREFS
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Cf. A195985, A195943, A195944, A195945, A195946, A195908, A195948, A007377, A008839, A030700, A030701, A030702, A030703, A030704, A030705, A030706.
Sequence in context: A134612 A025475 A246547 * A125643 A002760 A115651
Adjacent sequences: A195939 A195940 A195941 * A195943 A195944 A195945
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KEYWORD
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nonn,base,easy
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AUTHOR
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M. F. Hasler, Sep 25 2011
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STATUS
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approved
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