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 A050720 Number of nonzero palindromes of length n containing the digit '0'. 3
 0, 0, 9, 9, 171, 171, 2439, 2439, 30951, 30951, 368559, 368559, 4217031, 4217031, 46953279, 46953279, 512579511, 512579511, 5513215599, 5513215599, 58618940391, 58618940391, 617570463519, 617570463519, 6458134171671 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Table of n, a(n) for n=1..25. FORMULA G.f.: 9*x^3*(x+1) / ((3*x-1)*(3*x+1)*(10*x^2-1)). - Colin Barker, Feb 15 2013 For n > 1, a(n) = 9*10^(k-1) - 9^k, where k = ceiling(n/2). - Jon E. Schoenfield, Sep 14 2013 EXAMPLE For length 3 we find nine numbers: 101, 202, ... 909, so a(3) = 9. MATHEMATICA nzp[n_]:=Module[{k=Ceiling[n/2]}, 9*10^(k-1)-9^k]; Array[nzp, 30] (* Harvey P. Dale, Jun 01 2019 *) CROSSREFS Cf. A050683, A050686. Sequence in context: A092548 A121389 A065242 * A262860 A335026 A353182 Adjacent sequences: A050717 A050718 A050719 * A050721 A050722 A050723 KEYWORD nonn,base AUTHOR Patrick De Geest, Aug 15 1999 EXTENSIONS More terms from Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999 Corrected by T. D. Noe, Nov 08 2006 STATUS approved

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Last modified June 15 09:26 EDT 2024. Contains 373407 sequences. (Running on oeis4.)