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%I #10 Dec 20 2021 05:28:26
%S 1,2,3,8,5,4,14,15,24,10,12,13,16,6,7,17,26,18,9,11,19,20,21,22,23,25,
%T 27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,
%U 50,51,52,53,54,55,56,57,58,59,64,60,61,62,63,65,66,67,68,69
%N a(1) = 1. a(n) is the smallest unlisted number, the name of which contains the first letter of the name of a(n-1) in English.
%t name[n_]:=IntegerName[n,"Words"];a[1]=1;
%t a[n_]:=a[n]=Module[{i=1}, While[Or[MemberQ[Table[a[k],{k,1,n-1}],i],
%t !StringContainsQ[name[i],StringTake[name[a[n-1]],1]]],i++ ];i];
%t a/@Range[69] (* _Ivan N. Ianakiev_, Dec 20 2021 *)
%Y Cf. A277971.
%K easy,nonn,word
%O 1,2
%A _Ivan N. Ianakiev_, Nov 07 2016
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