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 A066776 Numbers n such that A043347(n) is a prime. 3
 1, 2, 3, 4, 69, 113 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS A043347(170) already has over a thousand digits. LINKS Table of n, a(n) for n=1..6. MATHEMATICA a[n_] := (k = Prime[ Floor[n^(3/2)]] + 6; l = Sum[ Prime[i], {i, 1, n - 1} ]; b = ""; Do[ b = StringJoin[b, ToString[ Prime[i]]], {i, 1, k} ]; Return[ ToExpression[ StringTake[ StringDrop[b, l], Prime[n]]]]); Do[ If[ PrimeQ[ a[n]], Print[n]], {n, 1, 180} ] CROSSREFS Sequence in context: A097930 A012322 A076519 * A115901 A073325 A142959 Adjacent sequences: A066773 A066774 A066775 * A066777 A066778 A066779 KEYWORD base,hard,nonn AUTHOR Joseph L. Pe, Jan 14 2002 STATUS approved

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Last modified December 2 14:17 EST 2023. Contains 367524 sequences. (Running on oeis4.)