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Topic: 2017 (Read 4243 times) 

towr
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Re: 2017
« Reply #25 on: Jan 3^{rd}, 2017, 10:20pm » 
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Oh yeah, wolfram alpha interprets log() as ln(), but it does have log10(). I suppose I could try to find ones without log. One the one hand, it does supply the function, but on the other hand only in a form that contains digits. And in many cases I need to put parenthesis around percentages, so 94 = (2^0) / (1%)  totient(7) should work.


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rloginunix
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Re: 2017
« Reply #26 on: Jan 4^{th}, 2017, 7:05pm » 
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Aah, an international pool of (interdisciplinary) confusion  logarithmic notation ... Separately, not hugely interesting, just some trivia I thought of while driving: if we construct a sum of powers of two then we get a nicely ordered set of initial odd integers: 2^{2} + 2^{0} + 2^{1} + 2^{7} = 135 The sum of (decimal) digits in bases 2 and 6 are equal (to 7), ditto bases 3 and 5 (9): (2017)_{2} = 11111100001, sums to 7 (2017)_{6} = 13201, sums to 7 (2017)_{3} = 2202201, sums to 9 (2017)_{5} = 31032, sums to 9


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towr
wu::riddles Moderator Uberpuzzler
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Re: 2017
« Reply #27 on: Jan 4^{th}, 2017, 10:35pm » 
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In bases 10, 19, 22, 25, 29, 33, 37, 43, 49, 57, 64, 73, 85, 97, 113, 127, 145, 169, 225, 253, 289, 337, 505, 673, 1009 the digits sum to 10 (in the same base) e.g 2017_{10} = [1][1008]_{1009} => 1_{1009}+1008_{1009}=10_{1009} = 1009_{10}

« Last Edit: Jan 4^{th}, 2017, 10:59pm by towr » 
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