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A280379 a(n) = A056171(k) - m, where k=prime(n) and m is the Ramanujan prime index to the greatest Ramanujan prime R(m) <= k. 1
0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 2, 0, 1, 1, 2, 0, 0, 1, 1, 0, 1, 0, 0, 1, 2, 2, 3, 2, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 2, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,30

COMMENTS

a(n)=0 corresponds to the Ramanujan prime R_m = A104272(m) = A056171(k).

LINKS

Table of n, a(n) for n=1..79.

FORMULA

a(n) = A056171(k) - m, where k=prime(n) and m is the Ramanujan prime index to the greatest Ramanujan prime R_m = A104272(m) <= k.

EXAMPLE

For prime(30)=113, A056171(113) = 14, 107 is R_12 and 127 is R_13, so 14 -12 = 2 (first occurrence).

PROG

(PARI) \\RR[x] is a list of Ramanujan primes, A104272.

{plimit=1.1*10^4; n=s=0;

forprime(p=2, plimit,

    s++;

    if(p==RR[n+1], n++);

    print1(s-primepi(floor(p/2))-n, ", ");

    )

}

CROSSREFS

Cf. A056171, A104272.

Sequence in context: A199954 A219987 A077614 * A180793 A116948 A101660

Adjacent sequences:  A280376 A280377 A280378 * A280380 A280381 A280382

KEYWORD

nonn

AUTHOR

John W. Nicholson, Jan 01 2017

STATUS

approved

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Last modified September 21 17:46 EDT 2019. Contains 327273 sequences. (Running on oeis4.)