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A008959 Final digits of squares: n^2 mod 10. 11
0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0, 1, 4, 9, 6, 5, 6, 9, 4, 1, 0 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

a(m*n)=a(m)*a(n) mod 10; a(5*n+k)=a(5*n-k) for k<=5*n. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 24 2009]

n^6 mod 10. [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Nov 06 2009]

a(n) = A002015(n) mod 10 = A174452(n) mod 10. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 21 2010]

LINKS

Index entries for sequences related to final digits of numbers

FORMULA

Periodic with period 10. - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Mar 13 2006

a(n)=1/5*{(n mod 10)+2*[(n+1) mod 10]+3*[(n+2) mod 10]-[(n+3) mod 10]+[(n+5) mod 10]+2*[(n+6) mod 10]-2*[(n+7) mod 10]-[(n+8) mod 10]} - Paolo P. Lava (paoloplava(AT)gmail.com), Nov 24 2006

a(n)=4.5 - (1 + 5^(1/2))*cos(Pi*n/5) + ( - 1 - 3/5*5^(1/2))*cos(2*Pi*n/5) + (5^(1/2) - 1)*cos(3*Pi*n/5) + ( - 1 + 3/5*5^(1/2))*cos(4*Pi*n/5) - 0.5*( - 1)^n [From Richard Choulet (richardchoulet(AT)yahoo.fr), Dec 12 2008]

MATHEMATICA

Table[Mod[n^2, 10], {n, 0, 200}] (* From Vladimir Joseph Stephan Orlovsky, Apr 21 2011 *)

PROG

(Other) sage: [power_mod(n, 6, 10)for n in xrange(0, 81)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Nov 06 2009]

CROSSREFS

a(n) = A010879(A000290(n)). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 04 2009]

Cf. A070431, A070435, A070438, A070442, A070452, A159852, A000290. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Apr 24 2009]

Sequence in context: A094090 A200632 A186723 * A169917 A059729 A184988

Adjacent sequences:  A008956 A008957 A008958 * A008960 A008961 A008962

KEYWORD

nonn,easy,base

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 16 19:23 EST 2012. Contains 205945 sequences.