Revision History for A183058
(Underlined text is an addition;
strikethrough text is a deletion.)
Showing entries 1-10
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#11 by Harvey P. Dale at Sat Jun 06 17:20:39 EDT 2020
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#10 by Harvey P. Dale at Sat Jun 06 17:20:36 EDT 2020
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| LINKS
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Harvey P. Dale, <a href="/A183058/b183058.txt">Table of n, a(n) for n = 1..2000</a>
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approved
editing
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#9 by Harvey P. Dale at Sat Jun 06 17:18:33 EDT 2020
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#8 by Harvey P. Dale at Sat Jun 06 17:18:30 EDT 2020
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| MATHEMATICA
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csgpQ[n_]:=Module[{idn=IntegerDigits[n], len}, len=Length[idn]; PrimeQ[2n+1]&&OddQ[len]&&idn[[(len+1)/2]]==0&&Count[idn, 0]==1]; Select[Prime[ Range[ 4500]], csgpQ] (* Harvey P. Dale, Jun 06 2020 *)
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approved
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#7 by Jon E. Schoenfield at Sat Jan 05 23:26:25 EST 2019
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#6 by Jon E. Schoenfield at Sat Jan 05 23:26:19 EST 2019
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| MAPLE
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for n from 0 to 50000 do if isA183058(n) then printf("%d, ", n); end if; end do: # : # _R. J. Mathar, _, Jan 05 2011
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approved
editing
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#5 by Russ Cox at Fri Mar 30 17:34:05 EDT 2012
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| AUTHOR
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_Omar E. Pol (info(AT)polprimos.com), _, Dec 26 2010
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Discussion
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| Fri Mar 30
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| OEIS Server: https://oeis.org/edit/global/157
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#4 by R. J. Mathar at Wed Jan 05 08:30:01 EST 2011
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#3 by R. J. Mathar at Wed Jan 05 08:29:46 EST 2011
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| NAME
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Cyclops-Sophie Sophie-Germain primes.
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| COMMENTS
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Intersection of Sophie Germain primes which are andalso Cyclops numbers.
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| MAPLE
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isA005384 := proc(n) isprime(n) and isprime(2*n+1) ; end proc:
isA134808 := proc(n) local dgs, ndgs; dgs := convert(n, base, 10) ; mdg := (nops(dgs)+1)/2 ; if type(nops(dgs), 'even') then false; elif n = 0 then true; else if op(mdg, dgs) <> 0 then false; else if mul(op(k, dgs), k=1..mdg-1) =0 or mul(op(k, dgs), k=mdg+1..nops(dgs)) = 0 then false; else true; end if; end if; end if; end proc:
isA183058 := proc(n) isA005384(n) and isA134808(n) ; end proc:
for n from 0 to 50000 do if isA183058(n) then printf("%d, ", n); end if; end do: # R. J. Mathar, Jan 05 2011
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#2 by Omar E. Pol at Sun Dec 26 10:39:23 EST 2010
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| NAME
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allocated for Omar E. Pol
Cyclops-Sophie Germain primes.
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| DATA
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509, 809, 12011, 12041, 13049, 14081, 16091, 18041, 21011, 21089, 22013, 22079, 23099, 25073, 28019, 29021, 29033, 31019, 33023, 33053, 35069, 35081, 35099, 36083, 37013, 37049, 38039, 39089, 41081, 42023, 42071, 42089, 43013
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| OFFSET
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1,1
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| COMMENTS
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Intersection of Sophie Germain primes and Cyclops numbers.
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| FORMULA
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A005384 INTERSECT A134808.
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| EXAMPLE
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509 is in the sequence because 509 is a Sophie Germain prime A005384 and it is also a Cyclops number A134808.
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| CROSSREFS
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Cf. A005384, A134808, A134809, A136098, A153807, A183059.
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| KEYWORD
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allocated
nonn,base
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| AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Dec 26 2010
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| STATUS
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approved
proposed
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