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A262555 Numbers n such that the concatenation of the decimal numbers 1 through n, but omitting 2, is a prime. 2
3, 41, 103, 1713, 2769 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The corresponding primes are the primes in A262572. Probabilistic arguments suggest the sequence is infinite.

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

The first two terms correspond to the primes 13 and 134567891011121314151617181920212223242526272829303132333435363738394041 (see A262298).

a(3) corresponds to a prime ending in 103, with 200 digits, a(4) to  a probable prime ending in 1713, with 5744 digits, and a(5) to a probable prime ending in 2769, with 9968 digits. These three terms were found by David Broadhurst on Oct 09 2015.

CROSSREFS

Cf. A262572, A262298, A007908.

Sequence in context: A092168 A080347 A229080 * A106978 A260832 A089131

Adjacent sequences:  A262552 A262553 A262554 * A262556 A262557 A262558

KEYWORD

nonn,base,more

AUTHOR

N. J. A. Sloane, Oct 09 2015

STATUS

approved

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Last modified May 28 21:38 EDT 2017. Contains 287241 sequences.