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Where records of A309036 occur.
3

%I #16 Apr 20 2020 05:35:16

%S 1,4,25,26,43,77,201,336,881,2144,22305,24113,44349,48748,153884,

%T 400161,793873,1195455,5066329,6227954,11394871,16233979,18368369,

%U 63843903,80998288,117335658,246252769,6420049930,23198011949,30432298548,62709861290,117888644809

%N Where records of A309036 occur.

%C Numbers m such that A309036(m) > A309036(k) for all k < m.

%H Giovanni Resta, <a href="/A309056/b309056.txt">Table of n, a(n) for n = 1..37</a>

%F A309055(n) = A309036(a(n)).

%e a(3) = 25 is a term because A309036(25) = 20 and A309036(k) < 20 for k < 25.

%p S1:= 0: S2:= 0: Recn:= NULL: count:= 0:

%p maxv:= 0:

%p for n from 1 to 200000 do

%p p:= ithprime(n);

%p S1:= S1 + p;

%p S2:= S2 + n*p;

%p v:= igcd(S1, S2);

%p if v > maxv then

%p maxv:= v;

%p count:= count+1;

%p Recn:= Recn, n;

%p fi

%p od:

%p Recn;

%o (PARI) lista(nn) = {my(k=r=s=t=0); forprime(p=2, nn, if(gcd(s+=p, t+=(k++)*p)>r, r=gcd(s,t); print1(k, ", "))); } \\ _Jinyuan Wang_, Apr 16 2020

%Y Cf. A309036, A309055.

%K nonn

%O 1,2

%A _Robert Israel_, Jul 09 2019

%E a(16)-a(27) from _Rémy Sigrist_, Jul 09 2019

%E a(28) from _Jinyuan Wang_, Apr 16 2020

%E Terms a(29) and beyond from _Giovanni Resta_, Apr 19 2020