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A214756
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a(n) = largest Ramanujan prime R_k in A104272 that is <= A002386(n).
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5
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2, 2, 2, 17, 71, 107, 503, 881, 1103, 1301, 9521, 15671, 19543, 31387, 155849, 360289, 370061, 492067, 1349147, 1356869, 2010553, 4652239, 17051297, 20831119, 47326519, 122164649, 189695483, 191912659
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OFFSET
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1,1
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COMMENTS
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While many values in A214757(n) are equal to A000101(n), here it seems the only value such that A002386(n) is equal to a(n) is a(1) = R_k = A002386(1) = 2.
See "Let rho(m) = A179196(m)" comment at A001223.
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LINKS
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Dana Jacobsen, Table of n, a(n) for n = 1..59
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EXAMPLE
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A104272(94) = 1301 < 1327 = A002386(10), so a(10) = 1301.
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PROG
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(Perl) use ntheory ":all"; sub a_from_2386 { my $n = shift; $n = prev_prime($n) while !is_ramanujan_prime($n); $n } # Dana Jacobsen, Jul 13 2016
(Perl) perl -Mntheory=:all -nE 'my $n=$1 if /(\d+)$/; $r=ramanujan_primes($n>1e6 ? $n-1e6 : 2, $n); say ++$x, " ", $r->[-1]; ' b002386.txt # Dana Jacobsen, Jul 13 2016
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CROSSREFS
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Cf. A002386, A104272, A001223.
Cf. A214925, A214926, A214757, A214924.
Sequence in context: A098919 A161748 A195871 * A079007 A064215 A087238
Adjacent sequences: A214753 A214754 A214755 * A214757 A214758 A214759
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KEYWORD
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nonn
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AUTHOR
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John W. Nicholson, Jul 27 2012
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EXTENSIONS
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Edited by N. J. A. Sloane, Aug 06 2012
a(16)-a(28) from Donovan Johnson, Nov 04 2012
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STATUS
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approved
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