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 A139367 a(n) = A102700(n) - A102342(n). 1
 1, 1, 2, 3, 2, 1, 3, 2, 4, 4, 6, 4, 4, 9, 8, 7, 7, 7, 7, 7, 5, 2, 3, 2, 2, 4, 4, 7, 10, 10, 9, 9, 8, 7, 5, 6, 9, 7, 13, 13, 13, 11, 12, 14, 15, 23, 16, 16, 16, 10, 10, 16, 13, 13, 13, 13, 12, 7, 10, 7, 1, 1, 1, 4, 6, 5, 9, 9, 13, 11, 16, 13, 13, 15, 13, 8, 9, 8, 10, 9, 10, 6, 7, 7, 10, 10, 11, 18 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS a(332) = -1. LINKS MAPLE From R. J. Mathar, Apr 25 2010: (Start) A102700 := proc(n) option remember; if n = 1 then 1; else for a from procname(n-1)+1 do if isprime(10*a+9) then return a; end if; end do: end if; end proc: A102342 := proc(n) option remember; if n = 1 then 0; else for a from procname(n-1)+1 do if isprime(10*a+7) then return a; end if; end do: end if; end proc: A139367 := proc(n) A102700(n)-A102342(n) ; end proc: seq(A139367(n), n=1..120) ; (End) CROSSREFS Sequence in context: A240224 A118105 A125211 * A117648 A037222 A107357 Adjacent sequences:  A139364 A139365 A139366 * A139368 A139369 A139370 KEYWORD sign AUTHOR Juri-Stepan Gerasimov, Jun 09 2008 EXTENSIONS Corrected (a 6 replaced by 7, a 7 by 9, a 13 by 16) and extended by R. J. Mathar, Apr 25 2010 STATUS approved

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