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A112749
Smallest prime of the form 5 followed by n copies of some k.
1
53, 577, 5333, 59999, 511111, 5111111111111, 59999999, 577777777, 5171717171717171717, 59999999999, 52727272727272727272727, 5111111111111, 53333333333333, 577777777777777, 5111111111111111
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 5333, 5 followed by three copies of 3.
MAPLE
cat3 := proc(a, b, n) local resu, i ; resu := a ; for i from 1 to n do resu := resu*10^( max(1, ilog10(b)+1) )+b ; od: RETURN(resu) ; end: A112749 := proc(n) local a, k; for k from 1 do a := cat3(5, k, n) ; if isprime(a) then RETURN(a) ; fi ; od: end: seq(A112749(n), n=1..20) ; # R. J. Mathar, Feb 08 2008
CROSSREFS
Sequence in context: A177120 A165555 A201855 * A245589 A177141 A096707
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jan 02 2006
EXTENSIONS
More terms from R. J. Mathar, Feb 08 2008
STATUS
approved