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Search: id:A115259
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| A115259 |
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Difference between the sum of digits in odd positions and the sum of digits in even positions of prime numbers. |
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+0
3
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| 2, 3, 5, 7, 0, 2, 6, 8, 1, 7, -2, 4, -3, -1, 3, -2, 4, -5, 1, -6, -4, 2, -5, 1, -2, 2, 4, 8, 10, 3, 6, -1, 5, 7, 6, -3, 3, -2, 2, -3, 3, -6, -7, -5, -1, 1, 2, 3, 7, 9, 2, 8, -1, -2, 4, -1, 5, -4, 2, -5, -3, -4, 10, 3, 5, 9, 1, 7, 6, 8, 1, 7, 4, -1, 5, -2, 4, 1, 5, 13, 12, 3, 2, 4, 10, 3, 9, 6, -1, 1, 5, 6, 3, -4, 4, 8, 14, 4, 6, 2, 8, 7, 2, 8, -1, 5, 4, -1, 5, 7
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Zero corresponds to the prime 11. It easy to show that there is no other zero: if the difference of odd-even digits of a number is zero, the number is a multiple of 11, i.e. it is not a prime.
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EXAMPLE
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a(37) = 3 because 37 th prime = 157, (7+1)-5 = 3;
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MAPLE
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seq(-sum(convert(ithprime(a), base, 10)[2*i], i=1..nops(convert(ithprime (a), base, 10))/2)-sum(convert(ithprime(a), base, 10)[2*i+1], i=0..(nops(convert (ithprime(a), base, 10))-1)/2)), a=1..N);
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CROSSREFS
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Cf. A040997, A005017, A063792, A087593, A042939, A041000, A040164, A115260, A115261.
Sequence in context: A020775 A041000 A042939 this_sequence A039709 A104250 A020919
Adjacent sequences: A115256 A115257 A115258 this_sequence A115260 A115261 A115262
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KEYWORD
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base,sign
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AUTHOR
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Giorgio Balzarotti and Paolo P. Lava (greenblue(AT)tiscali.it), Jan 20 2006
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