A066776 Numbers n such that A043347(n) is a prime.

1, 2, 3, 4, 69, 113

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