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A265559 Smallest base-2 palindrome m >= n, written in base 2. 1
0, 1, 11, 11, 101, 101, 111, 111, 1001, 1001, 1111, 1111, 1111, 1111, 1111, 1111, 10001, 10001, 10101, 10101, 10101, 10101, 11011, 11011, 11011, 11011, 11011, 11011, 11111, 11111, 11111, 11111, 100001, 100001, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 101101, 110011 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..46.

MAPLE

ispal:= proc(n) global b; # test if n is base-b pallindrome

  local L, Ln, i;

  L:= convert(n, base, b);

  Ln:= nops(L);

for i from 1 to floor(Ln/2) do

if L[i] <> L[Ln+1-i] then return(false); fi;

od:

return(true);

end proc;

# find min pal >= n, write in base 10

big10:=proc(n) global b;

local t1, t2, i, m, sw1, L1;

t1:=convert(n, base, b);

L1:=nops(t1);

for m from n to 10*n do

if ispal(m) then return(m); fi;

                       od;

lprint("no solution in big10 for n = ", n);

end proc;

# find min pal >= n, write in base 10

bigb:=proc(n) global b;

local t1, t2, i, m, mb, sw1, L1;

t1:=convert(n, base, b);

L1:=nops(t1);

for m from n to 10*n do

if ispal(m) then t2:=convert(m, base, b); mb:=add(t2[i]*10^(i-1), i=1..nops(t2)); return(mb); fi;

                       od;

lprint("no solution in big10 for n = ", n);

end proc;

b:=2;

[seq(big10(n), n=0..144)]; # A206914

[seq(bigb(n), n=0..144)]; # A265559

CROSSREFS

Sequences related to palindromic floor and ceiling: A175298, A206913, A206914, A261423, A262038, and the large block of consecutive sequences beginning at A265509.

See A206914 for the values of m written in base 10.

Sequence in context: A088761 A215256 A265526 * A265543 A062128 A286618

Adjacent sequences:  A265556 A265557 A265558 * A265560 A265561 A265562

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane, Dec 10 2015

STATUS

approved

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Last modified September 16 18:24 EDT 2019. Contains 327116 sequences. (Running on oeis4.)