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A101302 Primes of the form Sum_{k=1..n} phi(prime(k))). 1
3, 7, 13, 23, 149, 313, 619, 691, 769, 1237, 1451, 4391, 7639, 9787, 11527, 19489, 21943, 27997, 32869, 35449, 36107, 36767, 46817, 49939, 55691, 56543, 59119, 61757, 69127, 70079, 73973, 81047, 83117, 87337, 89491, 91673, 93871, 106537 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

a = {}; s = 0; Do[s = s + EulerPhi[ Prime[n]]; If[ PrimeQ[s], AppendTo[a, s]], {n, 200}]; a (* Robert G. Wilson v, Dec 22 2004 *)

CROSSREFS

Sequence in context: A084898 A147380 A146606 * A102948 A232533 A061263

Adjacent sequences:  A101299 A101300 A101301 * A101303 A101304 A101305

KEYWORD

nonn,easy

AUTHOR

Jorge Coveiro, Dec 22 2004

EXTENSIONS

Edited and extended by Robert G. Wilson v, Dec 22 2004

STATUS

approved

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Last modified February 22 23:44 EST 2020. Contains 332157 sequences. (Running on oeis4.)