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 A169821 a(n) = n*n in carryless arithmetic mod 9 in base 10. 2
 0, 1, 4, 0, 7, 7, 0, 4, 1, 0, 100, 121, 144, 160, 187, 117, 130, 154, 171, 100, 400, 441, 484, 430, 477, 427, 460, 414, 451, 400, 0, 61, 34, 0, 67, 37, 0, 64, 31, 0, 700, 781, 774, 760, 757, 747, 730, 724, 711, 700, 700, 711, 724, 730, 747, 757, 760, 774, 781, 700, 0, 31, 64 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Addition and multiplication are the same as in school, that is, done in base 10, except that there are no carries and individual digits are added or multiplied mod 9. LINKS EXAMPLE 13*13 = 160: ..13 ..13 ---- ..30 .13. ---- .160 ---- CROSSREFS Cf. A010878, A169908. See A170990 for a better version. Sequence in context: A117543 A242970 A070433 * A170990 A013666 A196533 Adjacent sequences:  A169818 A169819 A169820 * A169822 A169823 A169824 KEYWORD nonn,base AUTHOR David Applegate, Marc LeBrun and N. J. A. Sloane, Jul 11 2010 STATUS approved

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Last modified December 5 03:31 EST 2020. Contains 338943 sequences. (Running on oeis4.)