A206462 Primes p such that p + nextprime(p) is a squarefree number (A005117).

2, 13, 19, 37, 67, 89, 103, 109, 127, 163, 193, 199, 211, 229, 307, 379, 389, 397, 449, 463, 467, 479, 487, 499, 509, 613, 643, 661, 683, 701, 719, 739, 757, 769, 797, 859, 877, 883, 887, 911, 929, 937, 967, 983, 997, 1009, 1093, 1109, 1163, 1201, 1237, 1279

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n) + nextprime(a(n)) = A206329(n).

A008966(A001043(A049084(a(n)))) = 1. [Reinhard Zumkeller, Feb 08 2012]

Example

13 + 17 = 30 = A206329(2).

Mathematica

Prime[Select[Range[200], Abs[MoebiusMu[Prime[#] + Prime[# + 1]]] == 1 &]] (* Alonso del Arte, Feb 08 2012 *)

Prog

(Haskell)
a206462 n = a206462_list !! (n-1)
a206462_list = map (a000040 . (+ 1)) $
                   elemIndices 1 $ map a008966 a001043_list
-- Reinhard Zumkeller, Feb 08 2012

Crossrefs

Cf. A001043, A001358, A005117, A206329.

Sequence in context: A309663 A347259 A181686 * A339542 A020601 A298051

Adjacent sequences: A206459 A206460 A206461 * A206463 A206464 A206465

Keyword

nonn

Author

Zak Seidov, Feb 07 2012

Status

approved