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.

A256356 Composites in base 10 that remain composite in exactly two bases b, 2 <= b <= 10, expansions interpreted as decimal numbers.

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%I A256356 #16 Apr 09 2024 15:06:36
%S A256356 33247243,64037779,104865433,130237003,238561081,550677781,947051353,
%T A256356 1013991553,1246382791,1343122201,1607697631,1609062751,1632753601,
%U A256356 1788658063,2203645111,2364166213,2393866411,2480419783,2518589671,2544177511,2668538575,3029334883
%N A256356 Composites in base 10 that remain composite in exactly two bases b, 2 <= b <= 10, expansions interpreted as decimal numbers.
%C A256356 Are there any remaining composites in only one other base?
%H A256356 Sebastian Petzelberger, <a href="/A256356/b256356.txt">Table of n, a(n) for n = 1..150</a>
%H A256356 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_024.htm">PP&P Puzzle 24: Primes in several bases</a>
%Y A256356 Cf. A052026, A256350, A256351, A256352, A256353, A256354, A256355.
%Y A256356 Cf. A038537, A052027-A052033, A084482, A236356.
%K A256356 nonn,base,hard
%O A256356 1,1
%A A256356 _Sebastian Petzelberger_, Mar 25 2015