

A133758


Total number of restricted left truncatable primes in base n.


0




OFFSET

2,2


COMMENTS

Prime digits p in base n are counted if there is no prime with 2 digits which can have its leftmost digit removed to produce p, e. g. in base 10 the prime digits 2 and 5 are counted, because there are no primes containing them as rightmost digit.


REFERENCES

Steven Kahan; Sol Weintraub: Left truncatable primes. In: Journal of recreational mathematics 29 (1998), p. 254264.


LINKS

Table of n, a(n) for n=2..10.
I. O. Angell and H. J. Godwin, On Truncatable Primes, Math. Comput. 31, 265267, 1977.
Eric Weisstein's World of Mathematics, Truncatable Prime
Chai Wah Wu, On a conjecture regarding primality of numbers constructed from prepending and appending identical digits, arXiv:1503.08883 [math.NT], 2015.
Index entries for sequences related to truncatable primes


CROSSREFS

Cf. A076623, A055521.
Sequence in context: A167808 A161353 A182045 * A242288 A021742 A284867
Adjacent sequences: A133755 A133756 A133757 * A133759 A133760 A133761


KEYWORD

nonn


AUTHOR

Martin Renner, Jan 04 2008


STATUS

approved



