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A112748
Smallest prime of the form 4 followed by n copies of k.
1
41, 433, 4111, 47777, 42323232323, 4999999, 479797979797979, 43333333333333333, 4232323232323232323, 439393939393939393939, 48383838383838383838383, 4272727272727272727272727, 41111111111111
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 4111, 4 followed by three copies of 1.
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: A112748 := proc(n) local a, k; for k from 1 do a := cat3(4, k, n) ; if isprime(a) then RETURN(a) ; fi ; od: end: seq(A112748(n), n=1..20) ; # R. J. Mathar, Feb 08 2008
CROSSREFS
Sequence in context: A083761 A209823 A196784 * A173768 A061643 A209842
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jan 02 2006
EXTENSIONS
More terms from R. J. Mathar, Feb 08 2008
STATUS
approved