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Search: id:A094747
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| A094747 |
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Rearrangement of odd primes so that absolute successive differences are the least distinct even numbers. Priority is given to the least successive difference that has not occurred earlier. |
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2
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| 3, 5, 11, 7, 17, 29, 37, 23, 41, 61, 83, 67, 43, 71, 97, 127, 163, 131, 89, 137, 103, 59, 19, 73, 13, 79, 149, 199, 251, 307, 269, 223, 281, 349, 277, 353, 431, 367, 293, 373, 311, 229, 313, 227, 139, 47, 151, 241, 337, 239, 347, 449, 563, 463, 557, 673, 797, 691, 809
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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We interpret the definition as saying that we find a(n+1) from a(n) by testing a(n)-+2*d (first the minus, then the plus, d=1,2,3,4...., d not used before) for primality and for not already being on the list. This creates a list of odd primes, but there is no proof (yet) that all odd primes are in the sequence. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 29 2007
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MAPLE
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A094747 := proc(nmax) local a, diffs, d; a := [3] ; diffs := {} ; while nops(a) < nmax do d := 2 ; while true do if isprime(op(-1, a)-d) and not op(-1, a)-d in a and not abs(d) in diffs then a := [op(a), op(-1, a)-d] ; diffs := diffs union {d} ; break ; elif isprime(op(-1, a)+d) and not op(-1, a)+d in a and not abs(d) in diffs then a := [op(a), op(-1, a)+d] ; diffs := diffs union {d} ; break ; else d := d+2 ; fi ; od ; od; RETURN(a) ; end: A094747(100) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 29 2007
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CROSSREFS
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Cf. A094748.
Sequence in context: A073653 A145398 A087322 this_sequence A129738 A105603 A122133
Adjacent sequences: A094744 A094745 A094746 this_sequence A094748 A094749 A094750
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), May 24 2004
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 29 2007
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