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A097445 Second occurrence where n# - p is prime for primes p = 3,5,... 0
19, 197, 2293, 30011, 510463, 9699653, 223092809, 6469693163, 200560490051, 7420738134703, 304250263527157, 13082761331669881, 614889782588491313, 32589158477190044641, 1922760350154212638961, 117288381359406970983047 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

Care has to be taken to start with a large enough n to be sure terms are not missed. This was for n=100. This and A097444 were difficult to obtain using PARI.

LINKS

Table of n, a(n) for n=2..17.

FORMULA

n# is n primorial = product of primes 2*3*5*...*p<=n

EXAMPLE

3#=2*3 = 6. 6-3=3 first prime, 6-5 = 1 not prime thus 3#-p is omitted.

5# = 2*3*5 = 30. 30-7 = 23 first prime,30-11 = 19 second prime.

PROG

(PARI) primorm2(n) = { pr=1; for(x=1, n, f=1; pr*=prime(x); for(m=1, n, y=pr-prime(m); if(isprime(y), f=1; for(m=m+1, n, y=pr-prime(m); if(isprime(y), print1(y", "); f=0; break, f=1)); ); if(f==0, break) ) ) }

CROSSREFS

Sequence in context: A048556 A141995 A210339 * A238697 A256639 A058370

Adjacent sequences:  A097442 A097443 A097444 * A097446 A097447 A097448

KEYWORD

nonn

AUTHOR

Cino Hilliard, Aug 23 2004

STATUS

approved

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Last modified October 14 08:54 EDT 2019. Contains 327995 sequences. (Running on oeis4.)