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A105853
a(n) = sigma(n) (mod 10), i.e., unit's digit of sigma(n).
2
1, 3, 4, 7, 6, 2, 8, 5, 3, 8, 2, 8, 4, 4, 4, 1, 8, 9, 0, 2, 2, 6, 4, 0, 1, 2, 0, 6, 0, 2, 2, 3, 8, 4, 8, 1, 8, 0, 6, 0, 2, 6, 4, 4, 8, 2, 8, 4, 7, 3, 2, 8, 4, 0, 2, 0, 0, 0, 0, 8, 2, 6, 4, 7, 4, 4, 8, 6, 6, 4, 2, 5, 4, 4, 4, 0, 6, 8, 0, 6, 1, 6, 4, 4, 8, 2, 0, 0, 0, 4, 2, 8, 8, 4, 0, 2, 8, 1, 6, 7, 2, 6, 4, 0, 2
OFFSET
1,2
LINKS
FORMULA
a(n) = A010879(A000203(n)). - Michel Marcus, Jul 26 2017
MAPLE
A105853:=n->(numtheory)[sigma](n) mod 10: seq(A105853(n), n=1..180); # Wesley Ivan Hurt, Nov 07 2017
MATHEMATICA
Mod[DivisorSigma[1, Range[110]], 10] (* Harvey P. Dale, May 20 2019 *)
PROG
(PARI) a(n)=sigma(n)%10
CROSSREFS
Sequences sigma(n) mod k: A053866 (k=2), A074941 (k=3), A105824 (k=4), A105825 (k=5), A084301 (k=6), A105826 (k=7), A105827 (k=8), A105852 (k=9), A105853 (k=10).
Sequence in context: A077650 A244669 A316570 * A277216 A323394 A348977
KEYWORD
easy,nonn,base
AUTHOR
Shyam Sunder Gupta, May 05 2005
STATUS
approved