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A108831 Primes such that the outer 2 digits are n and n-1 and all inner digits are 4, where 0 < n < 9. 0
241, 443, 2441, 8447, 444443, 844447, 2444441, 444444443, 244444444441, 444444444443, 444444444444444444444444444443, 2444444444444444444444444444441, 44444444444444444444444444444443 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

PROG

(PARI) n10np1(n, d) = { local(x, y, k); for(x=1, n, for(k=1, 8, y=10^(x+1)*k+floor(10^x*d/9)*10+k-1; if(isprime(y), print1(y", ")) ) ) }

CROSSREFS

Sequence in context: A321582 A137771 A342681 * A068706 A157961 A142233

Adjacent sequences:  A108828 A108829 A108830 * A108832 A108833 A108834

KEYWORD

easy,nonn,base

AUTHOR

Cino Hilliard, Jul 11 2005

STATUS

approved

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Last modified May 17 12:55 EDT 2021. Contains 343971 sequences. (Running on oeis4.)