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A136296 "Special augmented primes": primes p such that the decimal number 1p1 is divisible by p. 1
11, 13, 137, 9091, 909091, 5882353, 909090909090909091, 909090909090909090909090909091, 9090909090909090909090909090909090909090909090909091 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Equals A116436 INTERSECT A000040. - R. J. Mathar, Apr 24 2008

The larger terms may be only probable primes. - Franklin T. Adams-Watters, Apr 23 2008

According to the Magma Calculator (http://magma.maths.usyd.edu.au/calc/), all nine terms given for this sequence are prime. - Jon E. Schoenfield, Aug 24 2009

REFERENCES

Clifford A. Pickover, A Passion for Mathematics, Wiley, 2005; see p. 61.

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

11371/137 = 83, an integer, so the prime 137 is a term.

PROG

(PARI) A136296k(k) = { local(l, d, lb, ub); d=factor(10^(k+1)+1)[, 1]; l=[]; lb=10^(k-1); ub=10*lb; for(i=1, #d, if(d[i]>=lb&&d[i]<ub, l=concat(l, [d[i]]))); l} l=[]; for(i=1, 60, l=concat(l, A136296k(i))); l \\ Franklin T. Adams-Watters, Apr 23 2008

CROSSREFS

Prime members of A116436.

Sequence in context: A276694 A086549 A108090 * A094621 A178426 A252170

Adjacent sequences:  A136293 A136294 A136295 * A136297 A136298 A136299

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Apr 20 2008

EXTENSIONS

a(4)-a(6) from M. F. Hasler, Apr 22 2008

More terms from Franklin T. Adams-Watters, Apr 23 2008

STATUS

approved

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Last modified July 13 16:22 EDT 2020. Contains 335688 sequences. (Running on oeis4.)