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.

A124434 LCM (least common multiple) of A001043 (sum of consecutive primes) and A001223 (difference of consecutive primes).

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%I A124434 #20 Jan 17 2019 09:20:50
%S A124434 5,8,12,36,24,60,36,84,156,60,204,156,84,180,300,336,120,384,276,144,
%T A124434 456,324,516,744,396,204,420,216,444,1680,516,804,276,1440,300,924,
%U A124434 960,660,1020,1056,360,1860,384,780,396,2460,2604,900,456,924,1416,480,2460
%N A124434 LCM (least common multiple) of A001043 (sum of consecutive primes) and A001223 (difference of consecutive primes).
%H A124434 Vincenzo Librandi, <a href="/A124434/b124434.txt">Table of n, a(n) for n = 1..10000</a>
%F A124434 a(n) = lcm((prime(n+1)+prime(n)), (prime(n+1)-prime(n))).
%F A124434 a(n) = (prime(n+1)^2 - prime(n)^2)/2 for n > 1. - _Jon Maiga_, Jan 17 2019
%e A124434 a(3)=12 because prime(3)=5, prime(4)=7 and lcm(7+5, 7-5) = lcm(12,2) = 12.
%t A124434 LCM[Total[#],#[[2]]-#[[1]]]&/@Partition[Prime[Range[60]],2,1] (* _Harvey P. Dale_, Apr 19 2013 *)
%t A124434 Join[{5}, Table[(Prime[n + 1]^2 - Prime[n]^2)/2, {n, 2, 59}]] (* _Jon Maiga_, Jan 17 2019 *)
%o A124434 (PARI) a(n) = my(p = prime(n), q = prime(n+1)); lcm(q+p, q-p); \\ _Michel Marcus_, Mar 15 2018
%Y A124434 Cf. A001223, A001043.
%K A124434 nonn,look
%O A124434 1,1
%A A124434 Mitch Cervinka (Mitch.Cervinka(AT)eds.com), Dec 15 2006