A285463 - OEIS

%I #13 Apr 28 2017 03:18:45

%S 349,936227,241853952611,248296403939,402089961397,14290027171787,

%T 22798543031501,25498249343221,928194481893587,1108961833390907,

%U 56735483914668107,56840981804535371,65947215239750827,67113509914884011,90309903454333957,97912610367958237,99307055366487077

%N Primes palindromic in base 8 that are the sum of 3 consecutive primes, the middle one palindromic in base 8.

%C Base 8 variant of A113846.

%C Similar arguments as for A113846 can be used to show that for all terms the first (and last) digit in base 8 is either 3 or 5.

%C All terms so far seem to follow one of the following patterns in base 8:

%C 3w3, where w is an odd-length word consisting of the digits 2 and 5 only or of the digits 1, 4, 7 only.

%C abwba, where a is either 3 or 5, b is either the empty word or a single digit from 0 to 7 and w is an odd-length word consisting of the digits 0, 3, 6 only or of the digits 1, 4, 7 only.

%C By searching only through these patterns, much larger terms were found such as 473953150492647002336509521341 = 576666333366030333030663333666675_3.

%H Chai Wah Wu, <a href="/A285463/b285463.txt">Table of n, a(n) for n = 1..35</a>

%H Chai Wah Wu, <a href="/A285463/a285463.txt">List of terms that are of the form 3w3 or abwba in base 8 (see comments for definitions)</a>

%Y Cf. A113846.

%K nonn,base,hard

%O 1,1

%A _Chai Wah Wu_, Apr 21 2017