Search: id:A113492
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%I A113492
%S A113492 1,11,1,5,7,1,2,10,1,3,2,22,9,1,1
%N A113492 Least integers, starting with 1, so ascending descending base exponent 
               transforms all 3-almost primes.
%C A113492 This is the 3-almost prime analogy to A113320.
%F A113492 a(1) = 1. For n>1: a(n) = min {n>0: SUM[from i = 1 to n] (a(i))^(a(n-i+1)) 
               is a 3-almost prime}. a(n) = min {n>0: SUM[from i = 1 to n] (a(i))^(a(n-i+1)) 
               in A014612}.
%e A113492 a(1) = 1 by definition.
%e A113492 a(2) = 11 because 1^11 + 11^1 = 12 = 2^2 * 3 is a 3-almost prime (A014612).
%e A113492 a(3) = 1 because 1^1 + 11^11 + 1^1 = 285311670613 = 97 * 40699 * 72271.
%e A113492 a(12) = 22 because 1^22 + 11^2 + 1^3 + 5^1 + 7^10 + 1^2 + 2^1 + 10^7 
               + 1^5 + 3^1 + 2^11 + 22^1 = 292477454 = 2 * 167 * 875681.
%e A113492 a(13) = 9 because 1^9 + 11^22 + 1^2 + 5^3 + 7^1 + 1^10 + 2^2 + 10^1 + 
               1^7 + 3^5 + 2^1 + 22^11 + 9^1 = 81402 749971 158062 525053 = 1559 
               * 792769 * 65863726957643.
%e A113492 a(14) = 1 because 1^1 + 11^9 + 1^22 + 5^2 + 7^3 + 1^1 + 2^10 + 10^2 + 
               1^1 + 3^7 + 2^5 + 22^1 + 9^11 + 1^1 = 33739011038 = 2 * 4649 * 3628631.
%e A113492 a(15) = 1 because 1^1 + 11^1 + 1^9 + 5^22 + 7^2 + 1^3 + 2^1 + 10^10 + 
               1^2 + 3^1 + 2^7 + 22^5 + 9^1 + 1^11 + 1^1 = 2384195796169465 = 5 
               * 22349 * 21336040057.
%Y A113492 Cf. A014612, A113320, A005408, A113122, A113153, A113154, A113336, A113271, 
               A113258, A113257, A113231, A087316, A113208.
%Y A113492 Sequence in context: A127991 A110305 A010199 this_sequence A010200 A086320 
               A095193
%Y A113492 Adjacent sequences: A113489 A113490 A113491 this_sequence A113493 A113494 
               A113495
%K A113492 easy,nonn
%O A113492 1,2
%A A113492 Jonathan Vos Post (jvospost3(AT)gmail.com), Jan 10 2006

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