The On-Line Encyclopedia of Integer Sequences (OEIS)

A176813 revision #9

A176813

Numbers n such that 3*A077800(2n-1)<p and p+2<3*A077800(2n) where A077800 is list of twin primes {p,p+2}.

1, 2, 7, 18, 60, 82, 149, 228, 229, 268, 325, 340, 372, 479, 508, 510, 515, 518, 619, 622, 710, 743, 790, 892, 910, 955, 998, 1020, 1158, 1184, 1215, 1266, 1310, 1363, 1431, 1478, 1567, 1885, 1921, 1979, 2066, 2316, 2476, 2541, 2688, 2704, 2781, 2798, 2809

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OFFSET

1,2

COMMENTS

Indices n of lower twin primes A001359(n) such that both members of some twin prime pair (p,p+2) are inside the open interval (3*A001359(n),3*A006512(n)). [R. J. Mathar, May 10 2010]

LINKS

Table of n, a(n) for n=1..49.

EXAMPLE

a(1)=1 because 3*A077800(2*1-1)=9<11 and 11+2<3*A077800(2*1)=15;

a(2)=2 because 3*A077800(2*2-1)=15<17 and 17+2<3*A077800(2*2)=21;

a(3)=7 because 3*A077800(2*7-1)=177<179 and 179+2<3*A077800(2*7)=183;

a(4)=18 because 3*A077800(2*18-1)=807<809 and 809+2<3*A077800(2*18)=813;

a(5)=60 because 3*A077800(2*60-1)=5847<5849 and 5849+2<3*A077800(2*60)=5853.

CROSSREFS

Sequence in context: A291255 A294004 A214836 * A000988 A185308 A002214

Adjacent sequences: A176810 A176811 A176812 * A176814 A176815 A176816

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Apr 26 2010

EXTENSIONS

Extended beyond 60 by R. J. Mathar, May 10 2010

STATUS

approved