This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A180552 #8 Mar 06 2016 13:26:00 %S A180552 5,7,53,59,73,79,251,271,353,359,373,379,509,569,571,653,673,709,751, %T A180552 769,1151,1171,1259,1279,1451,1471,1523,1579,1583,1723,1759,1783,2351, %U A180552 2371,2531,2549,2591,2731,2749,2791,3251,3271,3533,3539,3559,3593,3733 %N A180552 Primes that become a different prime under the mapping 5 <=> 7. %H A180552 Harvey P. Dale, <a href="/A180552/b180552.txt">Table of n, a(n) for n = 1..1000</a> %H A180552 <a href="/index/Pri#primes">Index to Primes</a>, Primes that become a different prime under some mapping. %t A180552 fQ[n_] := Block[{id = IntegerDigits@n}, (MemberQ[id, 5] || MemberQ[id, 7]) && PrimeQ[ FromDigits[ id /. {5 -> 7, 7 -> 5}] ]]; Select[ Prime@ Range@ 550, fQ] %Y A180552 Cf. A171039, A175791, A180517 thru A180559, A175789, A180560, A180561. %K A180552 base,nonn %O A180552 1,1 %A A180552 _Zak Seidov_ and _Robert G. Wilson v_, Sep 09 2010