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Search: id:A118497
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| A118497 |
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Primes that are not Chen primes written backwards. |
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1
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| 34, 16, 37, 97, 79, 301, 151, 361, 371, 391, 322, 922, 142, 172, 772, 382, 313, 133, 943, 763, 373, 383, 793, 124, 334, 934, 754, 364, 325, 745, 395, 106, 706, 316, 916, 346, 166, 376, 196, 907, 727, 337, 937, 757, 377, 328, 358, 958, 388, 709, 929, 769, 799
(list; graph; listen)
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OFFSET
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1,1
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MAPLE
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# Check if number is Chen prime ischenprime:=proc(n); if (isprime(n) = 'true') then if (isprime(n+2) = 'true' or numtheory[bigomega](n+2) = 2) then return 'true' else return 'false' fi fi end: #Reverse digits obrni_stev:=proc(n) local i, tren, tren1, st, ans; ans:=[ ]: tren:=n: tren1:=0: for i while (tren>0) do st:=round(10*frac(tren/10)): ans:=[op(ans), st]: tren:=trunc(tren/10): od: for i from 0 to nops(ans)-1 do tren1:= tren1 + op(nops(ans)-i, ans)*10^(i): od: return tren1 end: ts_inv_nonchen_pra:= proc(n) local i, trens, ans; trens:= [ ]; ans:=[ ]; for i from 1 to n do if (ischenprime( i ) = 'false') then ans:=[op(ans), obrni_stev(i)] fi: od: return ans end: ts_inv_nonchen_pra(2000);
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CROSSREFS
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Cf. A004087, A102540, A109611.
Sequence in context: A037933 A098765 A071788 this_sequence A033354 A033972 A114031
Adjacent sequences: A118494 A118495 A118496 this_sequence A118498 A118499 A118500
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KEYWORD
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nonn,base,less
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AUTHOR
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Jani Melik (jani_melik(AT)hotmail.com), May 05 2006
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