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 A335337 a(n) is the least k such that A335294(k) = n, or -1 if no such k exists. 1
 4, 1, 13, 229, 3259, 15739, 449569, 6958841, 130259903, 2404517671, 56014949761, 538155413969 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Conjecture: a(n) > 0 for all n. LINKS Table of n, a(n) for n=0..11. Altug Alkan, Andrew R. Booker, and Florian Luca, On a recursively defined sequence involving the prime counting function, arXiv:2006.08013 [math.NT], 2020. MATHEMATICA upto[nn_] := Block[{A = <|1->1|>, v, i=0, is=0, sp=2, p=2, s=1}, Print@{1, 1}; Do[ If[n == p, i++; p = NextPrime@ p]; v = i-is; If[! KeyExistsQ[A, v], A[v] = n; Print[{n, v}]]; s += v; While[s >= sp, is++; sp = NextPrime@ sp], {n, 2, nn}]; Last /@ Sort@ Normal@ A]; upto[450000] (* Giovanni Resta, Jun 02 2020 *) PROG (PARI) a(n) = { my (pn=0, ps=0, s=0, v); for (k=1, oo, pn+=isprime(k); v=if (k==1, 1, pn - ps); if (v==n, return (k)); ps+=sum(k=s+1, s+=v, isprime(k))) } \\ Rémy Sigrist, Jun 02 2020 CROSSREFS Cf. A335294. Sequence in context: A292270 A051928 A347486 * A226906 A327352 A050156 Adjacent sequences: A335334 A335335 A335336 * A335338 A335339 A335340 KEYWORD nonn,more AUTHOR Altug Alkan, Jun 02 2020 EXTENSIONS a(7)-a(11) from Giovanni Resta, Jun 02 2020 STATUS approved

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Last modified May 28 01:39 EDT 2023. Contains 362992 sequences. (Running on oeis4.)