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A194217 a(n) = A104272(n)-A080359(n). 4

%I #19 Aug 19 2018 09:34:32

%S 0,8,4,10,10,4,6,6,0,24,0,4,18,36,12,10,6,0,36,36,34,0,0,12,0,10,24,

%T 18,34,0,14,0,22,0,0,10,0,0,18,24,0,4,60,48,10,0,0,0,0,28,24,0,0,0,16,

%U 36,36,6,8,12,36,10,0,0,24,0,22,54,30,0,14,12,18,22

%N a(n) = A104272(n)-A080359(n).

%C Conjecture: Asymptotic density of nonzero terms is 3/4.

%H Alois P. Heinz, <a href="/A194217/b194217.txt">Table of n, a(n) for n = 1..1000</a>

%H V. Shevelev, <a href="http://arxiv.org/abs/0909.0715">Ramanujan and Labos primes, their generalizations and classifications of primes</a>

%H J. Sondow, <a href="http://mathworld.wolfram.com/RamanujanPrime.html">Ramanujan Prime</a>. (MathWorld)

%t nn = 100;

%t R = Table[0, {nn}]; s = 0;

%t Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s < nn, R[[s+1]] = k], {k, Prime[3nn]}

%t ];

%t A104272 = R = R + 1;

%t T = Table[0, {nn + 1}]; s = 0;

%t Do[If[PrimeQ[k], s++]; If[PrimeQ[k/2], s--]; If[s <= nn && T[[s+1]] == 0, T[[s+1]] = k], {k, Prime[3nn]}

%t ];

%t A080359 = Rest[T];

%t A104272 - A080359 (* _Jean-François Alcover_, Aug 19 2018, after _T. D. Noe_ *)

%Y Cf. A104272, A080359, A193507, A194184, A194186.

%K nonn

%O 1,2

%A _Vladimir Shevelev_, Aug 18 2011

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Last modified April 25 08:27 EDT 2024. Contains 371964 sequences. (Running on oeis4.)