cp's OEIS Frontend

A305715 Irregular triangle whose rows are all finite sequences of positive integers that are polydivisible and strictly pandigital.

%I A305715 #8 Jun 09 2018 08:43:01
%S A305715 1,1,2,1,2,3,3,2,1,1,2,3,6,5,4,3,2,1,6,5,4,3,8,1,6,5,4,7,2,3,8,1,6,5,
%T A305715 4,7,2,9,3,8,1,6,5,4,7,2,9,10
%N A305715 Irregular triangle whose rows are all finite sequences of positive integers that are polydivisible and strictly pandigital.
%C A305715 A positive integer sequence q of length k is strictly pandigital if it is a permutation of {1,2,...,k}. It is polydivisible if Sum_{i = 1...m} 10^(m - i) * q_i is a multiple of m for all 1 <= m <= k.
%D A305715 Matt Parker, Things to make and do in the fourth dimension, 2015, pages 7-9.
%H A305715 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polydivisible_number">Polydivisible number</a>
%e A305715 Triangle is:
%e A305715   {1}
%e A305715   {1,2}
%e A305715   {1,2,3}
%e A305715   {3,2,1}
%e A305715   {1,2,3,6,5,4}
%e A305715   {3,2,1,6,5,4}
%e A305715   {3,8,1,6,5,4,7,2}
%e A305715   {3,8,1,6,5,4,7,2,9}
%e A305715   {3,8,1,6,5,4,7,2,9,10}
%t A305715 polyQ[q_]:=And@@Table[Divisible[FromDigits[Take[q,k]],k],{k,Length[q]}];
%t A305715 Flatten[Table[Select[Permutations[Range[n]],polyQ],{n,8}]]
%Y A305715 Cf. A000670, A010784, A030299, A050289, A143671, A144688, A156069, A156071, A158242, A163574, A240763, A305701, A305712, A305714 (row lengths).
%K A305715 base,fini,tabf,full,nonn
%O A305715 1,3
%A A305715 _Gus Wiseman_, Jun 08 2018