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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Next term a(44)=10^348-32 (only probable prime with 15324 digits). a(110)=9999968. If n is divisible by 22 then either a(n)=0 or a(n)=10^x-b 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 * A181295 A166299 A182508

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

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Last modified June 25 08:34 EDT 2017. Contains 288709 sequences.