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A118497 Primes that are not Chen primes written backwards. 0
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; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..53.

MAPLE

# 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);

CROSSREFS

Cf. A004087, A102540, A109611.

Sequence in context: A300101 A298258 A298929 * A301826 A033354 A033972

Adjacent sequences:  A118494 A118495 A118496 * A118498 A118499 A118500

KEYWORD

nonn,base,less

AUTHOR

Jani Melik, May 05 2006

STATUS

approved

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Last modified October 20 02:21 EDT 2021. Contains 348099 sequences. (Running on oeis4.)