cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A160273 Successive differences (divided by 3) of the average of twin prime pairs divided by 2 (A040040).

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%I A160273 #24 Jul 03 2021 21:39:23
%S A160273 1,1,2,2,3,2,5,1,5,2,5,2,1,5,2,5,2,5,6,12,2,5,10,8,5,3,4,3,25,2,1,5,4,
%T A160273 23,2,3,2,5,10,13,8,2,2,3,18,4,5,1,20,2,8,5,4,11,14,1,9,3,8,5,9,1,4,3
%N A160273 Successive differences (divided by 3) of the average of twin prime pairs divided by 2 (A040040).
%C A160273 From _Eric Snyder_, Jul 02 2021: (Start)
%C A160273 Also the successive differences of A002822.
%C A160273 Instances of a(n) = 1 correspond to prime quadruples. (End)
%H A160273 Eric Snyder, <a href="/A160273/b160273.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Harvey P. Dale)
%p A160273 ZL := []; for p to 1000000 do if `and`(isprime(p), isprime(p+2)) then ZL := [op(ZL), ((p+2)^2-p^2)*(1/8)] end if end do; a := [seq((ZL[i+1]-ZL[i])*(1/3), i = 2 .. nops(ZL)-1)]
%t A160273 Rest[(Differences[(Mean/@Select[Partition[Prime[Range[500]],2,1], #[[2]]- #[[1]]==2&])/2])/3] (* _Harvey P. Dale_, Jun 10 2014 *)
%Y A160273 Cf. A040040, A002822.
%K A160273 nonn
%O A160273 1,3
%A A160273 _Stephen Crowley_, May 07 2009
%E A160273 Keyword "hard" deleted by _Harvey P. Dale_, Jun 10 2014