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%I #7 Feb 19 2023 14:00:33
%S 1,2,3,4,10,19,24,46,109,430,669,3245,6057,7837,33067,77777,476643,
%T 601855,3556550,5216954,15739663,41146179,189961757,882206624,
%U 3325059246,15581005618,23007498153,37607875618
%N a(n) is the index of the smallest prime whose digits sum to n-th prime.
%F a(n) = A000720(A054750(n)).
%F a(n) = min {k : A007605(k) = prime(n)}.
%e a(10) = 430 because prime(430) = 2999, 2 + 9 + 9 + 9 = 29 = prime(10) and this is the smallest such number.
%t Module[{nn=522*10^4,tbl},tbl=Table[{n,Total[IntegerDigits[Prime[n]]]},{n,nn}];Table[SelectFirst[tbl,#[[2]]==Prime[n]&],{n,20}]][[;;,1]] (* The program generates the first 20 terms of the sequence. *) (* _Harvey P. Dale_, Feb 19 2023 *)
%Y Cf. A000040, A000720, A007605, A028834, A046704, A046864, A054750, A075177.
%K nonn,base
%O 1,2
%A _Ilya Gutkovskiy_, Jul 19 2021