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A075693 Difference between 10-adic numbers defined in A018248 & A018247. 2
1, 5, -3, 9, -9, -7, 5, 7, 5, -7, 7, -9, -9, -1, 5, -3, -1, 5, 5, -9, 3, -5, -5, -9, -9, 7, -3, -3, 9, 7, 1, 9, 9, -9, 9, 7, -3, -9, -7, 9, 3, 5, 3, 5, 1, 3, 5, 1, -5, -1, -1, 9, 9, 9, 7, 7, -7, 3, -3, -7, 9, -7, -1, -9, 9, -1, -3, -3, 7, 5, -3, 9, 9, -9, -7, -9, 9, -1, -7, 3, -9, 5, 9, -7 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

Numbers in A018247 and A018248 are known as automorphic numbers in base 10, meaning that the infinite integers a=(...256259918212890625) or b=(...743740081787109376) provides a nontrivial solution to x*x == x (mod any power of 10).

Read backwards so as to match their counterparts (A007185 & A016090), A018247(1)+A018248(1) = 11 & A018247(n)+A018248(n) = 9 for all n's > 1 and their product is A076308.

All entries must be odd.

Is the accumulative sum equally positive and negative, i.e. does the sum equal 0 infinitely often?

MATHEMATICA

(* execute the programming in both A018247 & A018248 *) Reverse[b - a]

CROSSREFS

Cf. A018248 & A018247.

Sequence in context: A201938 A201410 A019955 * A198134 A082454 A108245

Adjacent sequences:  A075690 A075691 A075692 * A075694 A075695 A075696

KEYWORD

easy,sign

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 26 2002

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Last modified February 17 16:49 EST 2012. Contains 206058 sequences.