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A071196 The sum of the sequence starting with prime(n) and having prime sum defined in A071194, or -1 if no such sequence exists. 7
5, 127, 23, 31, 41, 101, 59, 71, 83, 97, 109, 479, 131, 263, 431, 173, 331, 199, 211, 223, 421, 251, 269, 719, 757, 311, 827, 587, 349, 647, 683, 1367, 733, 439, 457, 811, 487, 503, 2141, 1747, 941, 5009, 991, 1951, 607, 2053, 661, 1151, 21139, 701, 1753 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Rémy Sigrist, Colored logarithmic scatterplot of the first 10000 terms (where the color is function of A071194(n))

EXAMPLE

n=25: prime(25)=97, sum=97+101+103+107+109+113+127=757=a(25), prime; shorter (length>1) partial sums are composite: {97,198,301,408,517,630,757}.

MATHEMATICA

Table[sm = Prime[k] + Prime[k + 1]; g = 1; While[ ! PrimeQ[sm], g++; sm = sm + Prime[k + g]]; sm, {k, 1, 51}] (* Lei Zhou, Dec 02 2005 *)

PROG

(PARI) { forprime (p=2, prime(51), s=p; forprime (q=p+1, oo, if (isprime(s+=q), print1 (s", "); break))) } \\ Rémy Sigrist, Nov 17 2020

CROSSREFS

Cf. A000040, A071194, A071195, A071197, A071198.

Sequence in context: A156956 A015476 A059486 * A115233 A157438 A142803

Adjacent sequences:  A071193 A071194 A071195 * A071197 A071198 A071199

KEYWORD

nonn,look

AUTHOR

Labos Elemer, May 16 2002

EXTENSIONS

Edited and escape clause added by N. J. A. Sloane, Nov 17 2020~

STATUS

approved

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Last modified July 27 08:33 EDT 2021. Contains 346304 sequences. (Running on oeis4.)