A256475 - OEIS

%I #10 Mar 30 2015 21:42:53

%S 13,25,26,38,39,41,42,43,44,45,48,49,50,55,58,59,61,63,65,69,73,74,77,

%T 81,86,88,92,96,98,101,103,106,107,108,109,116,117,120,121,122,124,

%U 125,128,141,142,143,145,146,148,149,151,155,158,159,166,169,172,173,177,179,181,182,183,190,191,194,195,196,197,206

%N Numbers n for which there are more primes in range [prime(n)^2, prime(n)*prime(n+1)] than in range [prime(n)*prime(n+1), prime(n+1)^2].

%C Positions of negative terms in A256470.

%C Equally: Numbers n for which there are less primes in range [prime(n)*prime(n+1), prime(n+1)^2] than in range [prime(n)^2, prime(n)*prime(n+1)].

%H Antti Karttunen, <a href="/A256475/b256475.txt">Table of n, a(n) for n = 1..3084</a>

%t Select[Range@210, Count[Range[Prime[#]^2, Prime[#] Prime[# + 1]], _?PrimeQ] > Count[Range[Prime[#] Prime[# + 1], Prime[# + 1]^2], _?PrimeQ] &] (* _Michael De Vlieger_, Mar 30 2015 *)

%o (Scheme, with _Antti Karttunen_'s IntSeq-library)

%o (define A256475 (MATCHING-POS 1 1 (lambda (n) (negative? (A256470 n)))))

%Y Complement: A256474.

%Y Setwise difference of A256477 and A256471.

%Y Cf. A256485 (corresponding primes).

%Y Cf. A256470.

%K nonn

%O 1,1

%A _Antti Karttunen_, Mar 30 2015