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 A333770 Smallest palindromic number >= 3^n. 2
 1, 3, 9, 33, 88, 252, 737, 2222, 6666, 19691, 59095, 177771, 532235, 1594951, 4783874, 14355341, 43055034, 129141921, 387424783, 1162332611, 3486886843, 10460406401, 31381118313, 94143234149, 282429924282, 847288882748 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Robert Israel, Table of n, a(n) for n = 0..2093 FORMULA a(n) = A262038(A000244(n)). - Michel Marcus, May 04 2020 EXAMPLE a(10) = 59095, because 3^10 = 59049 and 59095 is the smallest palindromic number >= 59049. MAPLE digrev:= proc(n) local L, i;   L:= convert(n, base, 10);   add(L[-i]*10^(i-1), i=1..nops(L)) end proc: f:= proc(n) local d, x, y, t;   d:= ilog10(n)+1;   if d::even then     x:= floor(n/10^(d/2));     t:= x*10^(d/2)+digrev(x);     if t >= n then return t fi;     (x+1)*10^(d/2)+digrev(x+1);   else     x:= floor(n/10^((d-1)/2));     t:= x*10^((d-1)/2)+digrev(floor(x/10));     if t >= n then return t fi;     y:= x mod 10;     if y < 9 then return t + 10^((d-1)/2) fi;     x:= x+1;     x*10^((d-1)/2)+digrev(floor(x/10));   fi end proc: seq(f(3^i), i=0..30); # Robert Israel, May 04 2020 PROG (PARI) a(n) = for(k=3^n, oo, if(Vecrev(v=digits(k))==v, return(k))); CROSSREFS Cf. A000244, A002113, A262038, A333016. Sequence in context: A327808 A284964 A344247 * A281973 A219557 A094538 Adjacent sequences:  A333767 A333768 A333769 * A333771 A333772 A333773 KEYWORD easy,nonn,base AUTHOR Eder Vanzei, Apr 04 2020 STATUS approved

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Last modified January 22 15:13 EST 2022. Contains 350481 sequences. (Running on oeis4.)