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 A355967 Indices of the primes that occur in A104589. 1
 1, 3, 6, 25, 104, 634, 1236, 22613, 103409, 929044, 6298419, 80396036, 843325558, 5843115733, 24428345613, 515211289906, 4021634909249, 77930896716918, 387592118891917, 53467625139656294 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Table of n, a(n) for n=1..20. EXAMPLE The primes in A104589 are 2, 5, 13, 97, ... with prime indices 1, 3, 6, 25, ... MATHEMATICA s[1] = 1; s[n_] := s[n] = s[n - 1] + Sum[If[CompositeQ[s[k]], 0, s[k]], {k, 1, n - 1}]; PrimePi[Select[s /@ Range[200], PrimeQ[#] &]] (* Amiram Eldar, Jul 21 2022 *) PROG (PARI) lista(nn) = my(last=1, s = 1, list = List()); for (n=2, nn, last += s; if (isprime(last), s += last; listput(list, primepi(last))); ); Vec(list); CROSSREFS Cf. A000040, A000720, A104589, A355958. Sequence in context: A266549 A057730 A350752 * A074432 A212650 A297572 Adjacent sequences: A355964 A355965 A355966 * A355968 A355969 A355970 KEYWORD nonn,more AUTHOR Michel Marcus, Jul 21 2022 EXTENSIONS a(14)-a(20) from Amiram Eldar, Jul 21 2022 STATUS approved

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Last modified November 28 09:27 EST 2023. Contains 367412 sequences. (Running on oeis4.)