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A296420
Period of last digit of multiples of n.
0
1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10, 5, 10, 1, 10, 5, 10, 5, 2, 5, 10
OFFSET
0,2
COMMENTS
The list is periodic, with period 10.
EXAMPLE
a(6)=5 because multiples of 6 are 6, 12, 18, 24, 30, 36, 42 and the last digits of those numbers are 6,2,8,4,0,6,2,... with a period of 5.
MATHEMATICA
Array[10/GCD[#, 10] &, 77] (* Michael De Vlieger, Dec 23 2017 *)
PROG
(PARI) a(n) = 10/gcd(n, 10) \\ Iain Fox, Dec 11 2017
CROSSREFS
Cf. A054531.
Sequence in context: A147653 A152611 A241146 * A078267 A083950 A045617
KEYWORD
base,nonn
AUTHOR
Leonardo Sznajder, Dec 11 2017
EXTENSIONS
More terms from Michael De Vlieger, Dec 23 2017.
Term a(0) = 1 prepended by Halfdan Skjerning, Jun 18 2019
STATUS
approved