

A190501


Number of Ramanujan primes R_k such that 2^(n1) < R_k <= 2^n.


3



0, 1, 0, 0, 1, 2, 3, 6, 10, 19, 33, 62, 118, 208, 409, 740, 1418, 2676, 5043, 9638, 18248, 34949, 66752, 127880, 245489, 472113, 908302, 1751624, 3381546, 6534616, 12645372, 24490255, 47485123, 92152929, 178987716, 347943866, 676925069, 1317911597, 2567659990, 5005877954, 9765539069, 19062301793, 37230980158, 72756216207, 142253989491, 278275735952, 544621563320, 1066382258001
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OFFSET

0,6


LINKS

Dana Jacobsen, Table of n, a(n) for n = 0..56


PROG

(PARI) \\ With RR[.] is a list of A104272(.). The output of this program is (for n>=1) n, A190502(n), and RR[a(n)], a(n).
j=0; while(2^j<RR[10^8], {n=1; while(RR[n]<=2^j, n++); pn=n1; if(n<=1, print(j, " ", 0, " none"), print(j, " ", pn, " ", RR[pn], " ", pnpn2)); pn2=pn; j++});
(Perl) use ntheory ":all"; say "$_ ", ramanujan_prime_count(1 << $_)  ramanujan_prime_count(1 << ($_1)) for 0..56; # Dana Jacobsen, May 05 2017


CROSSREFS

Cf. A007053, A036378, A104272, A190502.
Sequence in context: A191519 A165920 A274160 * A026021 A291875 A227309
Adjacent sequences: A190498 A190499 A190500 * A190502 A190503 A190504


KEYWORD

nonn


AUTHOR

John W. Nicholson, May 11 2011


EXTENSIONS

Extended by T. D. Noe, May 11 2011
Modified the name as to match offset to A190502 and added leading term, John W. Nicholson, May 12 2011
Extended to n = 32 by John W. Nicholson, Dec 01 2012
Extended to n = 47, using A190502 data, by John W. Nicholson, Jan 31 2016


STATUS

approved



