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.

A031216 Write primes in base 10 but interpret as if in base 11.

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%I A031216 #19 Sep 01 2024 18:31:44
%S A031216 2,3,5,7,12,14,18,20,25,31,34,40,45,47,51,58,64,67,73,78,80,86,91,97,
%T A031216 106,122,124,128,130,135,150,155,161,163,174,177,183,190,194,201,207,
%U A031216 210,221,223,227,229,254,267,271,273,278,284,287,298,304,311
%N A031216 Write primes in base 10 but interpret as if in base 11.
%H A031216 Alois P. Heinz, <a href="/A031216/b031216.txt">Table of n, a(n) for n = 1..10000</a>
%F A031216 a(n) = A171397(prime(n)). - _Michel Marcus_, Aug 31 2024
%e A031216 13_10 = 11+2 -> 12_11, so 5th term is 12.
%p A031216 a:= n-> (l-> add(l[i]*11^(i-1), i=1..nops(l)))(convert(ithprime(n),base,10)):
%p A031216 seq(a(n), n=1..56);  # _Alois P. Heinz_, Aug 30 2024
%o A031216 (Python)
%o A031216 from sympy import prime
%o A031216 def A031216(n): return int(str(prime(n)),11) # _Chai Wah Wu_, Aug 30 2024
%o A031216 (PARI) a(n) = fromdigits(digits(prime(n)), 11); \\ _Michel Marcus_, Aug 31 2024
%Y A031216 Cf. A000040, A171397.
%K A031216 nonn,base
%O A031216 1,1
%A A031216 _Jeff Burch_
%E A031216 a(25) corrected by _Sean A. Irvine_, Apr 16 2020