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A261914 Largest palindrome < n (or 0 if n=0). 3
0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 22, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 33, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 44, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55, 55 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 0..20000

Index entries for sequences related to palindromes

FORMULA

a(n) = A261423(n-1) for all n>0. - M. F. Hasler, Sep 11 2015

MAPLE

# Pal has list of palindromes; palfloor is A261423

palfloor:=proc(n) global Pal; local i;

for i from 1 to nops(Pal) do

   if Pal[i]=n then return(n); fi;

   if Pal[i]>n then return(Pal[i-1]); fi;

od:

end;

prevpal:=proc(n) global palfloor;

if n=0 then return(0);

elif member(n, Pal) then return(palfloor(n-1));

else return(palfloor(n)); fi; end;

PROG

(Haskell)

a261914 n = a261914_list !! n

a261914_list = f 0 a002113_list where

   f n ps@(p:ps'@(p':_)) = p : f (n + 1) (if n < p' then ps else ps')

-- Reinhard Zumkeller, Sep 16 2015

CROSSREFS

Similar to but of course different from A261423.

Sequence in context: A072139 A266325 A262087 * A261423 A262040 A329200

Adjacent sequences:  A261911 A261912 A261913 * A261915 A261916 A261917

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Sep 10 2015

STATUS

approved

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Last modified June 4 17:50 EDT 2020. Contains 334828 sequences. (Running on oeis4.)