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Search: id:A117429
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%I A117429
%S A117429 4,4,25,123,626,3127,15623,78123,390623,1953122,9765627,48828127,
%T A117429 244140623,1220703121,6103515629,30517578127,152587890617,762939453119,
%U A117429 3814697265623,19073486328122,95367431640623
%N A117429 Semiprime nearest to 5^n. In case of a tie, choose the smaller.
%C A117429 Distance from 5^n to the nearest semiprime.
%F A117429 a(n) = 5^n + A117430(n). a(n) = 5^n + Min{k such that A001358(i) + k 
               = 5^n}.
%e A117429 a(0) = 4 because 5^0 + 3 = 4 = A001358(1) and no semiprime is closer 
               to 5^0.
%e A117429 a(1) = 4 because 5^1 - 1 = 4 = A001358(1) and no semiprime is closer 
               to 5^1.
%e A117429 a(2) = 25 because 5^2 + 0 = 25 = A001358(9), no semiprime is closer to 
               5^2.
%e A117429 a(3) = 123 because 5^3 - 2 = 123 = 3 * 41 = A00135842), no semiprime 
               is closer.
%e A117429 a(4) = 626 because 5^4 + 1 = 626 = 2 * 313, no semiprime is closer.
%e A117429 a(5) = 3127 because 5^5 + 2 = 3127 = 53 * 59, no semiprime is closer.
%e A117429 a(6) = 15623 because 5^6 - 2 = 15623 = 17 * 919, no semiprime is closer.
%e A117429 a(7) = 78123 because 5^7 - 2 = 78123 = 3 * 26041, no semiprime is closer.
%e A117429 a(8) = 390623 because 5^8 - 2 = 390623 = 73 * 5351, no semiprime is closer.
%e A117429 a(9) = 1953122 because 5^9 - 3 = 1953122 = 2 * 976561, no semiprime is 
               closer.
%e A117429 a(10) = 9765627 because 5^10 + 2 = 9765627 = 3 * 3255209, no semiprime 
               closer.
%Y A117429 Cf. A117416 = Semiprime nearest to 3^n, A117405 = Semiprime nearest to 
               2^n, A117387 = Prime nearest to 2^n.
%Y A117429 Cf. A000079, A001358, A117387, A117405, A117406, A117416, A117430.
%Y A117429 Sequence in context: A049614 A058166 A092897 this_sequence A132650 A112953 
               A110139
%Y A117429 Adjacent sequences: A117426 A117427 A117428 this_sequence A117430 A117431 
               A117432
%K A117429 easy,nonn,less
%O A117429 0,1
%A A117429 Jonathan Vos Post (jvospost3(AT)gmail.com), Mar 14 2006

    
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Last modified December 9 14:43 EST 2009. Contains 170430 sequences.


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