A073659 a(1) = 1; for n > 1, a(n) is the smallest even number not already in the sequence such that a(1) + ... + a(n) is a prime.

1, 2, 4, 6, 10, 8, 12, 16, 14, 24, 30, 22, 18, 26, 34, 36, 20, 28, 38, 40, 32, 42, 46, 48, 44, 52, 56, 60, 54, 58, 66, 50, 64, 62, 70, 84, 90, 72, 92, 76, 86, 94, 74, 88, 68, 82, 80, 102, 96, 100, 114, 98, 78, 112, 120, 110, 108, 106, 126, 122, 130, 132, 134, 124, 128, 118

Offset

1,2

Comments

Essentially the same as A054408. - R. J. Mathar, Dec 15 2008

Conjecture: Every even number appears. - N. J. A. Sloane, May 29 2017

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000 (terms n = 1..4097 from N. J. A. Sloane).

Mathematica

t = {1}; Do[i = 2; While[! PrimeQ[Total[t] + i] || MemberQ[t, i], i += 2]; AppendTo[t, i], {65}]; t (* Jayanta Basu, Jul 04 2013 *)

Prog

(PARI) v=[1]; n=1; while(n<200, if(isprime(n+vecsum(v))&&!vecsearch(vecsort(v), n), v=concat(v, n); n=0); n++); v \\ Derek Orr, Jun 01 2015

Crossrefs

Cf. A054408, A073660.

See A055265 for a version where the sums of two adjacent terms are primes.

Sequence in context: A242521 A338298 A366581 * A073661 A079052 A243502

Adjacent sequences: A073656 A073657 A073658 * A073660 A073661 A073662

Keyword

nonn,easy

Author

Amarnath Murthy, Aug 10 2002

Extensions

More terms from Sascha Kurz, Jan 28 2003

Offset corrected by Chai Wah Wu, Aug 27 2017

Status

approved