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A097931 Numbers in base 10 that are palindromic in bases 6 and 7.

%I A097931 #32 Mar 02 2019 02:24:14
%S A097931 0,1,2,3,4,5,92,135,178,185,5854,6148,7703,186621,204856,206620,
%T A097931 213970,269957,271721,279071,4252232,160258808,9689802280,
%U A097931 203509031168,204191148800,231773764784,321015775216,4102350269485,12262956787888
%N A097931 Numbers in base 10 that are palindromic in bases 6 and 7.
%C A097931 Intersection of A029953 and A029954. - _Michel Marcus_, Oct 09 2014
%H A097931 Giovanni Resta, <a href="/A097931/b097931.txt">Table of n, a(n) for n = 1..50</a> (first 30 terms from Robert G. Wilson v)
%H A097931 Cino Hilliard, <a href="http://groups.msn.com/BC2LCC/page.msnw?fc_p=%2FPari%20GP%20scripts&amp;fc_a=0">util.gp PARI Functions not in the PARI Library</a>. [broken link]
%H A097931 Cino Hilliard, <a href="/A097928/a097928.txt">Pari Utilities (cached)</a>
%e A097931 269957 base 10 is 5441445 base 6 and 269957 base 10 is 2203022 base 7.
%t A097931 Do[ p6 = IntegerDigits[n, 6]; If[ FromDigits[ Reverse[ p6]] == FromDigits[p6], p7 = IntegerDigits[n, 7]; If[ FromDigits[ Reverse[p7]] == FromDigits[p7], Print[n]]], {n, 10^9}] (* _Robert G. Wilson v_, Sep 07 2004 *)
%o A097931 (PARI) /* Requires reading the util.gp file in the link into the gp session.  */
%o A097931 palbase(n,b1,b2) = { for(x=1,n, if(ispal(base(10,b1,x))& ispal(base(10,b2,x)),print1(x",")) ) }
%Y A097931 Cf. A029953 (base 6), A029954 (base 7).
%K A097931 base,nonn
%O A097931 1,3
%A A097931 _Cino Hilliard_, Sep 04 2004
%E A097931 More terms from _Robert G. Wilson v_, Sep 07 2004
%E A097931 a(23)-a(29) from _Donovan Johnson_, Apr 23 2010
%E A097931 a(30) from _Robert G. Wilson v_, Jul 17 2015