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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; 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 (FrankTAW(AT)Netscape.net), Apr 23 2008

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

REFERENCES

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

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 (FrankTAW(AT)Netscape.net), Apr 23 2008

CROSSREFS

Prime members of A116436.

Sequence in context: A089824 A086549 A108090 * A094621 A178426 A144375

Adjacent sequences:  A136293 A136294 A136295 * A136297 A136298 A136299

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com), Apr 20 2008

EXTENSIONS

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

More terms from Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Apr 23 2008

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Last modified February 16 07:37 EST 2012. Contains 205878 sequences.