A228710 - OEIS

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A228710

Characteristic function of numbers with alternating parities of their digits in decimal representation.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1

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OFFSET

COMMENTS

a(A030141(n)) = 1; a(A228709(n)) = 0;

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Index entries for characteristic functions

FORMULA

For n > 9: a(n) * a(n+1) = 0 and 0 <= a(n) + a(n+1) <= 1.

PROG

(Haskell)

a228710 n = fromEnum $ f (n `div` 10) (n `mod` 2) where