cp's OEIS Frontend

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.

A235395 Primes whose decimal representation is a valid number in base 9 and interpreted as such is again a prime.

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%I A235395 #12 Nov 07 2016 12:36:48
%S A235395 2,3,5,7,41,47,67,131,151,241,331,337,461,557,601,641,661,751,757,827,
%T A235395 887,1031,1181,1217,1231,1321,1327,1367,1471,1637,1877,2027,2081,2111,
%U A235395 2131,2207,2281,2287,2351,2357,2647,2731,2861,3037,3121,3181,3187,3307,3347
%N A235395 Primes whose decimal representation is a valid number in base 9 and interpreted as such is again a prime.
%H A235395 Charles R Greathouse IV, <a href="/A235395/b235395.txt">Table of n, a(n) for n = 1..10000</a>
%H A235395 M. F. Hasler, <a href="https://docs.google.com/document/d/10IM7fcAbB2tqRGuwfGvuEGUzD_IXbgXPDK0tfxN4M3o/pub">Primes whose base c expansion is also the base b expansion of a prime</a>
%t A235395 Select[FromDigits@# & /@ IntegerDigits[ Prime@ Range@ 270, 9], PrimeQ]
%o A235395 (PARI) fixBase(n, oldBase, newBase)=my(d=digits(n, oldBase), t=newBase-1); for(i=1, #d, if(d[i]>t, for(j=i, #d, d[j]=t); break)); fromdigits(d, newBase)
%o A235395 list(lim)=my(v=List(), t); forprime(p=2, fixBase(lim\1, 10, 9), if(isprime(t=fromdigits(digits(p, 9), 10)), listput(v, t))); Vec(v) \\ _Charles R Greathouse IV_, Nov 07 2016
%Y A235395 Cf. A065727, A031974, A089971, A089981, A090707, A090708, A090709, A090710, A235394, A000040.
%K A235395 base,easy,nonn
%O A235395 1,1
%A A235395 _Robert G. Wilson v_, Jan 09 2014