The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A124434 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A124434

LCM (least common multiple) of A001043 (sum of consecutive primes) and A001223 (difference of consecutive primes).
(history; published version)

#20 by Bruno Berselli at Thu Jan 17 09:20:50 EST 2019

STATUS

reviewed

approved

#19 by Michel Marcus at Thu Jan 17 05:57:08 EST 2019

STATUS

proposed

reviewed

#18 by Jon Maiga at Thu Jan 17 05:44:24 EST 2019

STATUS

editing

proposed

#17 by Jon Maiga at Thu Jan 17 05:39:32 EST 2019

NAME

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

FORMULA

a(n) = (prime(n+1)^2 - prime(n)^2)/2 for n > 1. - Jon Maiga, Jan 17 2019

MATHEMATICA

Join[{5}, Table[(Prime[n + 1]^2 - Prime[n]^2)/2, {n, 2, 59}]] (* Jon Maiga, Jan 17 2019 *)

STATUS

approved

editing

Discussion

Thu Jan 17

05:44

Jon Maiga: A-numbers in name was swapped. The formula can be derived by similar reasoning as the Altug comment in A166011.

#16 by Alois P. Heinz at Sat Mar 17 23:11:12 EDT 2018

STATUS

editing

approved

#15 by Alois P. Heinz at Sat Mar 17 23:11:10 EDT 2018

KEYWORD

nonn,look,changed

STATUS

approved

editing

#14 by Alois P. Heinz at Sat Mar 17 23:10:44 EDT 2018

STATUS

proposed

approved

#13 by Jon E. Schoenfield at Sat Mar 17 23:04:11 EDT 2018

STATUS

editing

proposed

Discussion

Sat Mar 17

23:07

Alois P. Heinz: for me yes, all sequences are lists, they start with offset 1, ... so we can take n=1,2,3,...

#12 by Jon E. Schoenfield at Sat Mar 17 23:03:49 EDT 2018

FORMULA

a(n) = lcm((prime(n+1)+prime(n)), (prime(n+1)-prime(n))).

EXAMPLE

a(3)=12 because prime(3)=5, prime(4)=7 and lcm(7+5, 7-5) = lcm(12,2) = 12.

STATUS

approved

editing

Discussion

Sat Mar 17

23:04

Jon E. Schoenfield: Is the Name (which doesn't make any reference to "n") okay?

#11 by Bruno Berselli at Thu Mar 15 04:24:08 EDT 2018

STATUS

reviewed

approved