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A112642 Primorial number quotients arising in A007684: a(n) = A000210(A007684(n))/A000210(n-1). 1
6, 255255, 33426748355, 1357656019974967471687377449, 7105630242567996762185122555313528897845637444413640621, 1924344668948998025181489521338230544342953524990122861050411878226909135705454891961917517 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These numbers are (perhaps the smallest) squarefree solutions to Puzzle 329 of Rivera; a(n) is abundant, not divisible by the first n-1 prime numbers, i.e., the least prime divisor of a(n) is the n-th prime number.

LINKS

Table of n, a(n) for n=1..6.

C. Rivera, Puzzle 329. Odd abundant numbers not divided by 2 or 3.

FORMULA

a(n) = A000210(A007684(n))/A000210(n-1).

EXAMPLE

The corresponding sigma(a(n))/a(n) abundance ratios are as follows: 2, 2.27462, 2.00097, 2.01433, 2.00101, ...;

the terms have 2,3,5,7,11,... as least prime divisors.

CROSSREFS

Cf. A000210, A007684, A064001, A110585, A112640.

Sequence in context: A183765 A294325 A238821 * A067503 A079288 A072234

Adjacent sequences:  A112639 A112640 A112641 * A112643 A112644 A112645

KEYWORD

nonn

AUTHOR

Labos Elemer, Sep 19 2005

STATUS

approved

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Last modified May 26 11:08 EDT 2022. Contains 354086 sequences. (Running on oeis4.)