

A052079


Concatenation of n consecutive ascending numbers starting from a(n) produces the smallest possible prime of this form, 0 if no such prime exists.


3



2, 2, 0, 4, 15, 0, 7, 2, 0, 4, 129, 0, 5, 50, 0, 128, 3, 0, 23, 38, 0, 9998, 17, 0, 25, 2, 0, 16, 341, 0, 569, 42, 0, 14, 1203, 0, 2465, 102, 0, 212, 1161, 0, 197
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OFFSET

1,1


COMMENTS

Next term a(44)=10^34832 (only probable prime with 15324 digits). a(110)=9999968. If n is divisible by 22 then either a(n)=0 or a(n)=10^xb for some b<n.  Jens Kruse Andersen, Feb 03 2003


LINKS

Table of n, a(n) for n=1..43.
C. Rivera, Prime Puzzle 78


EXAMPLE

For n = 7 we have a(7) = 7 so the seven consecutive ascending numbers 7,8,9,10,11,12 and 13 concatenated together gives the smallest possible prime of this form, 78910111213.


CROSSREFS

Cf. A052077, A052078, A052080.
Sequence in context: A221609 A160125 A151868 * A291483 A181295 A166299
Adjacent sequences: A052076 A052077 A052078 * A052080 A052081 A052082


KEYWORD

nonn,base,hard


AUTHOR

Patrick De Geest, Jan 15 2000


EXTENSIONS

Terms a(7)a(43) calculated by Carlos Rivera and Felice Russo


STATUS

approved



