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A083555 Quotient of lcm of prime[n+1]-1 and prime[n]-1 and gcd of the same two numbers. 8
2, 2, 6, 15, 30, 12, 72, 99, 154, 210, 30, 90, 420, 483, 598, 754, 870, 110, 1155, 1260, 156, 1599, 1804, 132, 600, 2550, 2703, 2862, 756, 72, 4095, 4420, 4692, 5106, 5550, 650, 702, 6723, 7138, 7654, 8010, 342, 9120, 2352, 9702, 1155, 1295, 12543, 12882 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

a(n)=lcm[A006093(n+1), A006093(n)]/gcd[A006093(n+1), A006093(n)]= A083554(n)/A058263(n).

EXAMPLE

n=25: prime(25)=97,prime(26)=101; a(25)=LCM[96,100]/GCD[96,100]=2400/4=600

MATHEMATICA

f[x_] := Prime[x]-1 Table[LCM[f[w+1], f[w]]/GCD[f[w+1], f[w]], {w, 1, 128}]

CROSSREFS

Cf. A006093, A083538-A083554, A058263.

Sequence in context: A201687 A142471 A071208 * A001464 A067136 A180068

Adjacent sequences:  A083552 A083553 A083554 * A083556 A083557 A083558

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), May 22 2003

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.