A029953 -id:A029953 - cp's OEIS frontend

A342725 Numbers that are palindromic in base i-1.

0, 1, 13, 17, 189, 205, 257, 273, 3005, 3069, 3277, 3341, 4033, 4097, 4305, 4369, 48061, 48317, 49149, 49405, 52173, 52429, 53261, 53517, 64449, 64705, 65537, 65793, 68561, 68817, 69649, 69905, 768957, 769981, 773309, 774333, 785405, 786429, 789757, 790781, 834509

Offset: 1

Amiram Eldar, Mar 19 2021

Amiram Eldar, Table of n, a(n) for n = 1..512
Walter Penney, A "binary" system for complex numbers, Journal of the ACM, Vol. 12, No. 2 (1965), pp. 247-248.

Cf. A066321, A066323, A271472, A342726, A342727, A342728, A342729.

Similar sequences: A002113 (decimal), A006995 (binary), A014190 (base 3), A014192 (base 4), A029952 (base 5), A029953 (base 6), A029954 (base 7), A029803 (base 8), A029955 (base 9), A046807 (factorial base), A094202 (Zeckendorf), A331191 (dual Zeckendorf), A331891 (negabinary), A333423 (primorial base).

v = {{0, 0, 0, 0}, {0, 0, 0, 1}, {1, 1, 0, 0}, {1, 1, 0, 1}}; q[n_] := PalindromeQ @ FromDigits[Flatten @ v[[1 + Reverse @ Most[Mod[NestWhileList[(# - Mod[#, 4])/-4 &, n, # != 0 &], 4]]]]]; Select[Range[0, 10^4], q]

13 is a term since its base-(i-1) presentation is 100010001 which is palindromic.

A249155 Palindromic in bases 6 and 15.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 7, 14, 80, 160, 301, 602, 693, 994, 1295, 1627, 1777, 2365, 2666, 5296, 5776, 6256, 17360, 34720, 51301, 52201, 105092, 155493, 209284, 587846, 735644, 7904800, 11495701, 80005507, 80469907, 83165017, 89731777, 90196177

Offset: 1

Ray Chandler, Oct 27 2014

Intersection of A029953 and A029960.

			301 is a term since 301 = 1221 base 6 and 301 = 151 base 15.

Ray Chandler and Chai Wah Wu, Table of n, a(n) for n = 1..71 (terms < 6^28). First 65 terms from Ray Chandler.
Attila Bérczes and Volker Ziegler, On Simultaneous Palindromes, arXiv:1403.0787 [math.NT], 2014.

Cf. A007632, A060792, A249156, A249157, A249158.

palQ[n_Integer, base_Integer] := Block[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[10^6] - 1, palQ[#, 6] && palQ[#, 15] &]

from gmpy2 import digits
def palQ(n, b): # check if n is a palindrome in base b
    s = digits(n, b)
    return s == s[::-1]
def palQgen(l, b): # generator of palindromes in base b of length <= 2*l
    if l > 0:
        yield 0
        for x in range(1, l+1):
            for y in range(b**(x-1), b**x):
                s = digits(y, b)
                yield int(s+s[-2::-1], b)
            for y in range(b**(x-1), b**x):
                s = digits(y, b)
                yield int(s+s[::-1], b)
A249155_list = [n for n in palQgen(8, 6) if palQ(n, 15)] # Chai Wah Wu, Nov 29 2014

A333423 Numbers that are palindromes in primorial base.

Original entry on oeis.org

0, 1, 3, 7, 9, 11, 31, 39, 47, 211, 217, 223, 229, 235, 243, 249, 255, 261, 267, 275, 281, 287, 293, 299, 2311, 2347, 2383, 2419, 2455, 2523, 2559, 2595, 2631, 2667, 2735, 2771, 2807, 2843, 2879, 30031, 30061, 30091, 30121, 30151, 30181, 30211, 30247, 30277, 30307

Offset: 1

Amiram Eldar, Mar 20 2020

			3 is a term since its representation in primorial base is 11 (1 * 2# + 1) which is a palindrome.
7 is a term since its representation in primorial base is 101 (1 * 3# + 0 * 2# + 1 = 6 + 1) which is a palindrome.

Amiram Eldar, Table of n, a(n) for n = 1..2500
Wikipedia, Primorial number system.
Index entries for sequences related to primorial base.

Cf. A049345, A235168.

Cf. A002113, A006995, A014190, A014192, A029952, A029953, A029954, A029803, A029955, A046807.

max = 6; bases = Prime @ Range[max, 1, -1]; nmax = Times @@ bases - 1; Select[Range[0, nmax], PalindromeQ @ IntegerDigits[#, MixedRadix[bases]] &]

A256086 Non-palindromic balanced numbers in base 6.

Original entry on oeis.org

234, 276, 318, 326, 368, 410, 451, 493, 535, 543, 585, 627, 668, 710, 752, 760, 802, 844, 885, 927, 969, 977, 1019, 1061, 1102, 1144, 1186, 1308, 1344, 1380, 1416, 1452, 1488, 1530, 1566, 1602, 1638, 1674, 1710, 1730, 1752, 1766, 1788, 1802, 1824, 1838, 1860, 1874, 1896, 1910, 1932, 1952, 1974, 1988

Offset: 1

M. F. Hasler, Mar 14 2015

Here a number is called balanced if the sum of digits weighted by their arithmetic distance from the "center" is zero. Since palindromes (A029953) are trivially balanced, they are excluded here.

This is the base-6 variant of the decimal version A256075 invented by Eric Angelini. See there, and the base-2 version A256082, for further information and examples.

Robert Israel, Table of n, a(n) for n = 1..10000

Cf. A256082 - A256089, A256075, A256076, A256080, A029953.

filter:= proc(n) local L, m,i;
  L:= convert(n, base, 6);
  m:= (1+nops(L))/2;
add(L[i]*(i-m), i=1..nops(L))=0  and L <> ListTools:-Reverse(L)
end proc:
select(filter, [$1..10000]); # Robert Israel, Nov 04 2024

is(n,b=6,d=digits(n,b),o=(#d+1)/2)=!(vector(#d,i,i-o)*d~)&d!=Vecrev(d)

A046236 Cubes which are palindromes in base 6.

Original entry on oeis.org

0, 1, 343, 50653, 10218313, 2181825073, 470366406433, 101566487155393, 21937185733709953, 4738389801656378113, 1023490673757369487873, 221073930689208859487233

Offset: 1

Patrick De Geest, May 15 1998

Note that '7'^3 = '1331{6}' = '363{10}' = '292{11}' is a palindromic street !

Patrick De Geest, World!Of Numbers, Palindromic cubes in bases 2 to 17.

Intersection of A029953 and A000578.

Cf. A046235.

pal6Q[n_]:=Module[{idn6=IntegerDigits[n,6]},idn6==Reverse[idn6]]; Select[ Range[ 0,6047*10^4]^3,pal6Q] (* Harvey P. Dale, Jun 01 2022 *)

a(n) = A046235(n)^3. - Andrew Howroyd, Aug 10 2024

Offset corrected by Andrew Howroyd, Aug 10 2024

A260184 Numbers n written in base 10 that are palindromic in exactly three bases b, 2 <= b <= 10 and not simultaneously bases 2, 4 and 8.

Original entry on oeis.org

9, 10, 21, 40, 55, 80, 85, 100, 130, 154, 164, 178, 191, 203, 235, 242, 255, 257, 273, 282, 292, 300, 328, 400, 455, 585, 656, 819, 910, 2709, 6643, 8200, 14762, 32152, 53235, 74647, 428585, 532900, 1181729, 1405397, 4210945, 5259525, 27711772, 719848917, 43253138565

Offset: 1

Giovanni Resta and Robert G. Wilson v, Jul 17 2015

			273 is in the sequence because 100010001_2 = 101010_3 = 10101_4 = 2043_5 = 1133_6 = 540_7 = 421_8 = 333_9 = 273_10 and three of the bases, namely 2, 4 & 9, yield palindromes.

Cf. A214426, A214425.

(* see A214425 and set all terms as lst, then *)
gQ[n_] := Count[ palQ[n,#] & /@ {2, 4, 8}, True];
Select[ lst, gQ[#] != 3 &]

The intersection of A006995, A014190, A014192, A029952, A029953, A029954, A029803, A029955 & A002113 which yields just three members, not simultaneously bases 2, 4 and 8.

A043265 Sum of the digits of the n-th base 6 palindrome.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 2, 4, 6, 8, 10, 2, 3, 4, 5, 6, 7, 4, 5, 6, 7, 8, 9, 6, 7, 8, 9, 10, 11, 8, 9, 10, 11, 12, 13, 10, 11, 12, 13, 14, 15, 2, 4, 6, 8, 10, 12, 4, 6, 8, 10, 12, 14, 6, 8, 10, 12, 14, 16, 8, 10, 12, 14, 16, 18, 10, 12, 14, 16, 18, 20, 2, 3, 4

Offset: 1

Clark Kimberling

A029953 (base 6 palindromes)

Total/@Select[IntegerDigits[#,6]&/@Range[0,2000],#==Reverse[#]&] (* Harvey P. Dale, Apr 18 2020 *)

cp's OEIS Frontend

A342725 Numbers that are palindromic in base i-1.

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A249155 Palindromic in bases 6 and 15.

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A333423 Numbers that are palindromes in primorial base.

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A256086 Non-palindromic balanced numbers in base 6.

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A046236 Cubes which are palindromes in base 6.

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A260184 Numbers n written in base 10 that are palindromic in exactly three bases b, 2 <= b <= 10 and not simultaneously bases 2, 4 and 8.

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A043265 Sum of the digits of the n-th base 6 palindrome.

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