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A065255
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Consider the sequence b(k) such that b(k) and sigma(b(k)) end with the same digit in base 10. Sequence gives values of b(k) such that b(k)/k = 10.
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1
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40, 290, 600, 790, 1350, 1400, 4580, 4590, 4640, 4740, 4750, 9080, 9480, 9570, 9600, 11000, 11020, 11080, 11160, 11210, 11240, 11290, 11310, 11570, 11590, 11720, 11780, 11800, 13870, 13880, 13990, 14060, 14250, 14290, 14310, 14320, 14340, 14590, 14760, 15920, 16390
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OFFSET
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1,1
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COMMENTS
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Conjecture: lim n -> infinity b(k)/k = 10.
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LINKS
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EXAMPLE
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b(k) begins 1,14,34,40,44,74,78,81,84 hence b(4)=40 and 40/4=10 so 40 is in the sequence.
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PROG
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(PARI) upto(n) = {my(b = List(), res = List(), t = 0); forfactored(i = 1, n, s = sigma(i[2]); if((s - i[1])%10 == 0, t++; if(10*t == i[1], listput(res, i[1])))); res} \\ David A. Corneth, Aug 23 2023
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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