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A106586
Digit next to last in squares ending in 6.
0
1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7, 7, 5, 9, 3, 1, 1, 3, 9, 5, 7
OFFSET
1,2
COMMENTS
Entries are always one of the odd digits 1,3,5,7,9.
Palindrome of period 10. [From Paul Curtz, Jan 04 2009]
FORMULA
G.f. -x*(1 +2*x +7*x^2 -2*x^3 +9*x^4 -2*x^5 +7*x^6 +2*x^7 +x^8) / ( (x-1) *(1+x+x^2+x^3+x^4) *(1-x+x^2-x^3+x^4) ). - R. J. Mathar, Jul 28 2013
MATHEMATICA
Mod[Floor[ #^2/10], 10] & /@ Select[Range[700], Mod[ #^2, 10] == 6 &] (* Ray Chandler, May 13 2005 *)
CROSSREFS
Cf. A000290.
Sequence in context: A320960 A193075 A285264 * A010633 A332564 A199053
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, May 10 2005
EXTENSIONS
Extended by Ray Chandler, May 13 2005
STATUS
approved