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A248583 The least number m == 1 (mod 6) that is divisible by prime(n). 0

%I

%S 25,7,55,13,85,19,115,145,31,37,205,43,235,265,295,61,67,355,73,79,

%T 415,445,97,505,103,535,109,565,127,655,685,139,745,151,157,163,835,

%U 865,895,181,955,193,985,199,211,223,1135,229,1165,1195,241,1255,1285,1315,1345,271,277,1405,283,1465,307

%N The least number m == 1 (mod 6) that is divisible by prime(n).

%C If a(n) is not prime then a(n)=5*prime(n).

%F a(n) = (4*floor((mod(prime(n),6)+4)/6)+1)*prime(n). - _Farideh Firoozbakht_, Oct 09 2014

%e a(3)=25 because p=prime(3)=5 and 25= 5*5=1+4*6

%e a(5)=55 because p=prime(5)=11 and 55= 11*5=1+9*6

%e a(200)=6115 because p=prime(200)=1223 and 6115=1223*5=1+1019*6.

%t Table[ChineseRemainder[{0, 1}, {Prime[n], 6}], {n, 3, 200}]

%t (*or*)Table[p = Prime[n]; If[Mod[p, 6] > 1, 5*p, p], {n, 3, 200}]

%t Table[p=Prime[n];(4Floor[(Mod[p,6]+4)/6]+1)*p,{n,3,63}](* _Farideh Firoozbakht_, Oct 09 2014 *)

%Y Cf. A002476, A016921.

%K nonn

%O 3,1

%A _Zak Seidov_, Oct 09 2014

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Last modified May 22 22:13 EDT 2022. Contains 353959 sequences. (Running on oeis4.)