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A332731 a(n) is the smallest positive k such that n!*prime(n) - k is a prime. 1
1, 1, 1, 1, 11, 11, 1, 13, 1, 17, 1, 1, 53, 17, 1, 29, 23, 31, 23, 1, 29, 67, 31, 31, 43, 29, 181, 1, 83, 41, 101, 79, 179, 79, 43, 83, 47, 83, 163, 79, 53, 73, 59, 67, 347, 223, 67, 53, 97, 1, 157, 73, 1, 229, 101, 1, 263, 103, 101, 163, 139, 599, 103, 197, 73, 433, 313, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,5

COMMENTS

Equivalently, a(n) = n!*prime(n) minus the previous prime.

LINKS

Table of n, a(n) for n=2..69.

FORMULA

a(n) = n!*prime(n) - A007917(n!*prime(n)).

EXAMPLE

For n=3, n!*prime(n) = 3!*prime(3) = 6*5 = 30, and the largest prime < 30 is 29, so a(3) = 30 - 29 = 1.

PROG

(PARI) a(n) = my(x=n!*prime(n)); x - precprime(x); \\ Michel Marcus, Feb 22 2020

CROSSREFS

Cf. A000040, A000142, A007917, A332733.

Sequence in context: A287288 A287979 A268915 * A322270 A260589 A291367

Adjacent sequences:  A332728 A332729 A332730 * A332732 A332733 A332734

KEYWORD

nonn

AUTHOR

Mohamed Sami Gattoufi, Feb 21 2020

STATUS

approved

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Last modified September 26 23:23 EDT 2021. Contains 347673 sequences. (Running on oeis4.)