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A124434 LCM (least common multiple) of A001043 (sum of consecutive primes) and A001223 (difference of consecutive primes). 3
5, 8, 12, 36, 24, 60, 36, 84, 156, 60, 204, 156, 84, 180, 300, 336, 120, 384, 276, 144, 456, 324, 516, 744, 396, 204, 420, 216, 444, 1680, 516, 804, 276, 1440, 300, 924, 960, 660, 1020, 1056, 360, 1860, 384, 780, 396, 2460, 2604, 900, 456, 924, 1416, 480, 2460 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

FORMULA

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

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

EXAMPLE

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

MATHEMATICA

LCM[Total[#], #[[2]]-#[[1]]]&/@Partition[Prime[Range[60]], 2, 1] (* Harvey P. Dale, Apr 19 2013 *)

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

PROG

(PARI) a(n) = my(p = prime(n), q = prime(n+1)); lcm(q+p, q-p); \\ Michel Marcus, Mar 15 2018

CROSSREFS

Cf. A001223, A001043.

Sequence in context: A026279 A260966 A338547 * A180930 A185729 A164128

Adjacent sequences: A124431 A124432 A124433 * A124435 A124436 A124437

KEYWORD

nonn,look

AUTHOR

Mitch Cervinka (Mitch.Cervinka(AT)eds.com), Dec 15 2006

STATUS

approved

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Last modified January 28 20:13 EST 2023. Contains 359905 sequences. (Running on oeis4.)