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Search: id:A072570
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| A072570 |
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Even interprimes i = (p+q)/2 (where p, q are consecutive primes) such that (q-p)/2 is not divisible by 3. |
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+0
3
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| 4, 6, 12, 18, 30, 42, 60, 72, 102, 108, 120, 138, 144, 150, 180, 186, 192, 198, 228, 240, 246, 270, 282, 288, 300, 312, 324, 342, 348, 414, 420, 426, 432, 462, 522, 552, 570, 582, 600, 618, 636, 642, 660, 696, 714, 780, 792, 810, 816, 822, 828, 834, 846, 858
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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A superset of A014574. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Mar 03 2009]
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FORMULA
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d = (P_n+1 - P_n)/2 is even & d == +/- 1 (mod 6).
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MATHEMATICA
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a = Table[Prime[n], {n, 2, 200}]; b = {}; Do[d = (a[[n + 1]] - a[[n]])/2; If[ EvenQ[ a[[n]] + d] && (Mod[d, 6] == 5 || Mod[d, 6] == 1), b = Append[b, a[[n]] + d]], {n, 1, 198}]; b
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CROSSREFS
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Cf. A024675, A072571. A072568 is union of A072571 and this sequence.
Sequence in context: A068570 A074998 A061715 this_sequence A014574 A034425 A073123
Adjacent sequences: A072567 A072568 A072569 this_sequence A072571 A072572 A072573
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KEYWORD
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nonn
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AUTHOR
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Marco Matosic (marcomatosic(AT)hotmail.com), Jun 24 2002
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EXTENSIONS
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Edited by N. J. A. Sloane (njas(AT)research.att.com) and Robert G. Wilson v (rgwv(AT)rgwv.com), Jun 27 2002
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