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 A307221 Positions of records in A306440. 1
 0, 1, 6, 30, 36, 540, 2100, 3780, 15120, 37800, 85680, 120960, 126000, 131040, 196560, 302400, 332640, 786240, 917280, 1179360, 2702700, 3341520, 4324320, 8648640, 19656000, 19958400, 21205800, 43243200, 46781280, 57657600, 64864800, 122522400, 151351200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Numbers k such that A306440(k) > A306440(j) for all j < k. LINKS Giovanni Resta, Table of n, a(n) for n = 1..50 EXAMPLE a(3) = 6 is in the sequence because A306440(6) = 2 while A306440(j) < 2 for 0 <= j < 6. MAPLE A306440:= proc(n) local t;     nops(select(t -> t^2<2*n and isprime(t+1) and isprime(2*n/t+1), numtheory:-divisors(2*n))) end proc: Res:= 0: vmax:= 0: for n from 1 to 10^6 do   v:= A306440(n);   if v > vmax then     Res:= Res, n; vmax:= v;   fi od: Res; MATHEMATICA A306440[n_] := Length[Select[Divisors[2n], #^2 < 2n && PrimeQ[#+1] && PrimeQ[2n/#+1]&]]; Res = {0}; vmax = 0; For[n = 1, n <= 10^6 , n++, v = A306440[n]; If[v > vmax, Print[n]; AppendTo[Res, n]; vmax = v]]; Res (* Jean-François Alcover, Oct 17 2020, translated from Maple *) CROSSREFS Cf. A306440. Sequence in context: A062515 A316532 A325374 * A062268 A067879 A334900 Adjacent sequences:  A307218 A307219 A307220 * A307222 A307223 A307224 KEYWORD nonn AUTHOR Robert Israel, Mar 29 2019 EXTENSIONS a(24)-a(33) from Daniel Suteu, Mar 29 2019 STATUS approved

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Last modified May 18 23:41 EDT 2021. Contains 344009 sequences. (Running on oeis4.)