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 A197421 Primes of the form sum_{k=1..n} prime(k)*prime(k+1). 3
 44839, 60859, 130411, 204749, 303767, 902971, 1027969, 1471633, 2514257, 3658769, 6908719, 7415743, 21966317, 28168523, 32413109, 37049567, 44034163, 47856331, 373881787, 425445073, 443609813, 564963589, 732111109, 758871401, 857997893, 995046653, 2489902577 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The corresponding values of n are 22, 24, 30, 34, 38, 52, 54, 60, 70, 78, 94, 96, .... LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..2243 EXAMPLE For n = 22, a(1) = 44839 = 2*3 + 3*5 + 5*7 + ....+ 79*83 where 79 = prime(22) and 83 = prime(23). MAPLE p:=0:for n from 1 to 600 do:p:=p+ithprime(n)*ithprime(n+1): if type(p, prime)=true then printf(`%d, `, p): else fi:od: MATHEMATICA Select[Table[Sum[Prime[k] Prime[k + 1], {k, n}], {n, 400}], PrimeQ] (* Alonso del Arte, Oct 14 2011 *) PROG (PARI) v=List(); t=0; p=2; forprime(q=3, 1e4, if(isprime(t+=p*q), listput(v, t)); p=q); Vec(v) \\ Charles R Greathouse IV, Oct 14 2011 CROSSREFS Primes in A074745. Cf. A013918. Sequence in context: A225814 A209909 A251790 * A197614 A202987 A183590 Adjacent sequences:  A197418 A197419 A197420 * A197422 A197423 A197424 KEYWORD nonn AUTHOR Michel Lagneau, Oct 14 2011 EXTENSIONS Incorrect a(2243) and beyond removed from b-file by Andrew Howroyd, Feb 27 2018 STATUS approved

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Last modified January 22 19:15 EST 2022. Contains 350488 sequences. (Running on oeis4.)