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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.
a(6) > 10000, if it exists. - Robert Price, Nov 04 2018
LINKS
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
Sequence in context: A360930 A229080 A289270 * A343814 A106978 A260832
KEYWORD
nonn,base,more
AUTHOR
N. J. A. Sloane, Oct 09 2015
STATUS
approved

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Last modified March 28 08:00 EDT 2024. Contains 371235 sequences. (Running on oeis4.)