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Powerful numbers (A001694) made of nontrivial runs of identical digits.
2

%I #15 Mar 11 2024 04:20:37

%S 7744,665500,774400,5556600,6655000,7744000,55566000,66550000,

%T 77440000,447722888,448855888,555660000,665500000,774400000,

%U 1155775544,5500002244,5511005500,5556600000,6655000000,7744000000,11000004488,11122233444,22244466888

%N Powerful numbers (A001694) made of nontrivial runs of identical digits.

%C A run of length 1 is trivial.

%H Amiram Eldar, <a href="/A116064/b116064.txt">Table of n, a(n) for n = 1..201</a> (terms below 10^18)

%H <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a>.

%e 448855888 = 2^4*13^3*113^2.

%Y Intersection of A001694 and A033023.

%K nonn,base

%O 1,1

%A _Giovanni Resta_, Feb 13 2006

%E a(16)-a(23) from _Donovan Johnson_, Jun 29 2011