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A091081 Numbers n which when converted to base 7, reversed and converted back to base 10 yield a number m such that n mod m = 0. Cases which are trivial or result in digit loss are excluded. 6

%I #5 Oct 10 2014 08:19:00

%S 36,288,1800,2052,2304,12384,14400,16416,86472,88236,99072,100836,

%T 115200,605088,619200,691776,705888,806688,4235400,4247748,4323600,

%U 4335948,4840704,4853052,4928904,4941252,5534208,5647104,29647584,29746368,30254400,30353184

%N Numbers n which when converted to base 7, reversed and converted back to base 10 yield a number m such that n mod m = 0. Cases which are trivial or result in digit loss are excluded.

%C Trivial cases are those numbers which upon conversion result in a number which is palindromic (m = reverse(m)), or a palindrome plus trailing zeros such that m = reverse(m)*10^z where z=number of lost zeros. Nontrivial digit loss occurs when a converted number has trailing zeros that drop off when the number is reversed.

%H C. Seggelin, <a href="http://www.plastereddragon.com/maths/asortdiv.htm">Numbers Divisible by Digit Permutations</a>. [Broken link]

%e a(1) = 36 because: 36 in base 7 is 51; 51 reversed is 15; 15 converted back to base 10 is 12 and 36 mod 12 = 0.

%o (PARI) /* See A091077 and use PARI script with b=7 */

%Y Cf. A091077 (same in base 3), A091078 (base 4), A091079 (base 5), A091080 (base 6), A091082 (base 8), A091083 (base 9), A031877 (base 10).

%K base,nonn

%O 1,1

%A Chuck Seggelin (barkeep(AT)plastereddragon.com), Dec 18 2003

%E More terms from _Michel Marcus_, Oct 10 2014

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Last modified April 23 08:33 EDT 2024. Contains 371905 sequences. (Running on oeis4.)