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%I #11 Aug 01 2019 13:45:06
%S 0,3,5,7,39,11,13,3515,17,19,3721,23,525,3927,29,31,31133,5735,37,
%T 31339,41,43,3591545,47,749,31751,53,51155,31957,59,61,3792163,51365,
%U 67,32369,71,73,35152575,71177,79,392781,83,51785,32987,89,71391,33193
%N Replace 2n+1 with concatenation of its divisors >1.
%H Harvey P. Dale, <a href="/A037287/b037287.txt">Table of n, a(n) for n = 0..1000</a>
%e Divisors of 15 are 1,3,5,15, so a(7)=3515
%t Join[{0},Table[FromDigits[Flatten[IntegerDigits/@Rest[Divisors[2n+1]]]],{n,50}]] (* _Harvey P. Dale_, Aug 01 2019 *)
%K nonn,base,easy
%O 0,2
%A _N. J. A. Sloane_
%E More terms from _Erich Friedman_