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A066776
Numbers n such that A043347(n) is a prime.
2
1, 2, 3, 4, 69, 113
OFFSET
1,2
COMMENTS
A043347(170) already has over a thousand digits.
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
KEYWORD
base,hard,nonn
AUTHOR
Joseph L. Pe, Jan 14 2002
STATUS
approved