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A247253
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First differences of A251239.
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11
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1, 6, 6, 7, 1, 7, 13, 8, 10, 1, 17, 8, 1, 13, 13, 13, 5, 10, 11, 5, 9, 8, 19, 10, 11, 7, 11, 5, 9, 27, 9, 13, 5, 23, 5, 9, 17, 9, 11, 11, 7, 21, 9, 7, 5, 17, 27, 11, 7, 9, 17, 5, 13, 9, 21, 11, 7, 13, 9, 9, 17, 31, 7, 7, 9, 29, 9, 25, 5, 7, 13, 15, 15, 11
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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COMMENTS
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Conjecture 1: a(n) > 0, since presumably primes occur in A098550 in natural order;
Conjecture 2: it seems that a(n) = 1 only for n = 1, 5, 10 and 13;
Conjecture 3: a(n) - 1 = number of composite terms between prime(n) and prime(n+1) in A098550;
Conjecture 5: Apart from first term, this is equal to the sequence of run lengths in A251549. These run lengths begin 2, 6, 6, 7, 1, 7, 13, 8, 10, 1, 17, 8, 1, 13, 13, 13, 5, 10, 11, 5, 9, ... . - N. J. A. Sloane, Dec 18 2014
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LINKS
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PROG
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(Haskell)
a247253 n = a247253_list !! (n-1)
a247253_list = zipWith (-) (tail a251239_list) a251239_list
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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