A115095 - OEIS

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A115095

Positions of 4 in A038800.

1, 2, 11, 20, 83, 149, 188, 209, 326, 347, 566, 944, 1301, 1565, 1574, 1607, 1805, 1892, 1943, 2102, 2228, 2531, 3173, 3485, 4379, 5135, 5534, 6299, 6722, 6950, 7223, 7727, 7970, 8105, 8273, 8882, 9785, 9914, 10112, 10985, 11654, 11930, 12221, 13547

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OFFSET

1,2

COMMENTS

Starting with a(2)=2, numbers m such that 10(m-1)+{1,3,7,9} are all primes.

Essentially the same as A064975. [From R. J. Mathar, Aug 11 2008]

REFERENCES

4 is maximal possible number of primes between 10n and 10(n+1).

LINKS

Table of n, a(n) for n=1..44.

EXAMPLE

11 is OK because 10(11-1)+{1,3,7,9} = 101,103,107,109 all prime.