

A060370


Ratios (p1)/d, where p is a prime and d is the number of digits of the periodic part of the decimal expansion of 1/p.


2



1, 2, 4, 1, 5, 2, 1, 1, 1, 1, 2, 12, 8, 2, 1, 4, 1, 1, 2, 2, 9, 6, 2, 2, 1, 25, 3, 2, 1, 1, 3, 1, 17, 3, 1, 2, 2, 2, 1, 4, 1, 1, 2, 1, 2, 2, 7, 1, 2, 1, 1, 34, 8, 5, 1, 1, 1, 54, 4, 10, 2, 2, 2, 2, 1, 4, 3, 1, 2, 3, 11, 2, 1, 2, 1, 1, 1, 4, 2, 2, 1, 3, 2, 1, 2
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OFFSET

1,2


COMMENTS

The sequence of 2nd, 4th and following terms coincides with A006556, which gives the "number of different cycles of digits in the decimal expansions of 1/p, 2/p, ..., (p1)/p where p = nth prime different from 2 or 5".


LINKS

Carmine Suriano and T. D. Noe, Table of n, a(n) for n = 1..10000 (first 101 terms from Carmine Suriano)


FORMULA

a(n) = (b(n)1)/c(n), where b(n) and c(n) are the nth terms of A000040 and A048595 respectively.


EXAMPLE

a(13) = 40/5 = 8, since 41 is the 13th prime and the periodic part of 1/41 = 0.02439024390... consists of 5 digits.


MATHEMATICA

Join[{1, 2, 4}, Table[p = Prime[n]; (p  1)/Length[RealDigits[1/p, 10][[1, 1]]], {n, 4, 100}]] (* T. D. Noe, Oct 04 2012 *)


CROSSREFS

Cf. A000040, A060283, A048595, A006556.
Sequence in context: A077623 A132042 A303977 * A318704 A165064 A299918
Adjacent sequences: A060367 A060368 A060369 * A060371 A060372 A060373


KEYWORD

nonn,base


AUTHOR

Klaus Brockhaus, Apr 01 2001


STATUS

approved



