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A072969 Least k > 0 such that the last digit of k^n is the same as the last digit of n^k. 0
1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9, 10, 1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9, 10, 1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9, 10, 1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9, 10, 1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..99.

FORMULA

a(n) is a periodic sequence with period (1, 2, 3, 2, 5, 4, 7, 4, 9, 10, 1, 4, 7, 4, 5, 2, 3, 2, 9, 10, ) of length 20

PROG

(PARI) a(n)=if(n<0, 0, k=1; while(abs(k^n%10-n^k%10)>0, s++); s)

CROSSREFS

Sequence in context: A195637 A181861 A212831 * A139712 A175856 A075365

Adjacent sequences:  A072966 A072967 A072968 * A072970 A072971 A072972

KEYWORD

base,easy,nonn

AUTHOR

Benoit Cloitre, Aug 13 2002

STATUS

approved

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Last modified April 22 08:25 EDT 2019. Contains 322329 sequences. (Running on oeis4.)