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A177835
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Primes p for which a smaller prime q exists with A000120(q) >= 2*A000120(p)-1.
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2
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17, 37, 41, 67, 73, 97, 131, 137, 139, 149, 163, 193, 197, 257, 263, 269, 277, 281, 293, 337, 353, 389, 401, 449, 521, 523, 547, 577, 593, 641, 643, 673, 769, 773, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1091, 1093, 1097, 1109, 1123, 1129, 1153, 1163, 1171
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OFFSET
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1,1
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COMMENTS
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LINKS
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MAPLE
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read("transforms") ; A000120 := proc(n) wt(n) ; end proc:
isA177835 := proc(p) if isprime(p) then q := 2 ; while q < p do if A000120(q) >= 2*A000120(p)-1 then return true; end if; q := nextprime(q) ; end do: return false; else false; end if; end proc:
for i from 1 to 2000 do if isA177835(ithprime(i)) then printf("%d, ", ithprime(i)) ; end if; end do: # R. J. Mathar, May 31 2010
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MATHEMATICA
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With[{b = DigitCount[Prime[Range[200]], 2, 1]}, Rest@ Prime[Position[2*b - 1 - FoldList[Max, b], _?(# <= 0 &)] // Flatten]] (* Amiram Eldar, Jul 25 2023 *)
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CROSSREFS
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KEYWORD
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nonn,easy,base
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AUTHOR
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EXTENSIONS
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keyword:base and more terms added by R. J. Mathar, May 31 2010
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STATUS
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approved
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