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 A073124 a[n]=prime[1+prime(n)]-prime[prime[n]]. 8

%I

%S 2,2,2,2,6,2,2,4,6,4,4,6,2,2,12,10,4,10,6,6,6,8,2,2,12,10,6,6,2,2,10,

%T 4,14,12,4,4,10,4,6,2,6,4,10,10,12,6,4,14,6,4,10,12,8,4,6,24,10,6,2,8,

%U 14,18

%N a[n]=prime[1+prime(n)]-prime[prime[n]].

%C Number of entries in {x,..} such that PrimePi[x]=Prime[n].

%F a(n) = Card{x; A000720(x) = A000040(n)}

%e n = 25: p(25) = 97, Pi[x] = 97 holds for 12 numbers: X = {509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519, 520} so a(25) = 12. Largest 520 = A073123(25), smallest = A006450(25).

%t Table[Prime[Prime[n]+1]-Prime[Prime[n]], {n, 1, 256}]

%Y Cf. A000720, A000040, A006450, A073123.

%Y a[n]=A072677(n)-A006450(n)

%K nonn

%O 1,1

%A Labos E. (labos(AT)ana.sote.hu), Jul 16 2002

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