cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-5 of 5 results.

A378000 Array read by ascending antidiagonals: T(n,k) is the k-th positive integer that is digitally balanced in base n.

Original entry on oeis.org

2, 11, 9, 75, 15, 10, 694, 78, 19, 12, 8345, 698, 99, 21, 35, 123717, 8350, 714, 108, 260, 37, 2177399, 123723, 8375, 722, 114, 266, 38, 44317196, 2177406, 123759, 8385, 738, 120, 268, 41, 1023456789, 44317204, 2177455, 123771, 8410, 742, 135, 278, 42
Offset: 2

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Author

Paolo Xausa, Nov 14 2024

Keywords

Comments

A digitally balanced number in base b contains every digit from 0 to b-1 in equal amount.

Examples

			Array begins:
  n\k|           1            2            3            4            5  ...
  -------------------------------------------------------------------------
   2 |           2,           9,          10,          12,          35, ... = A031443
   3 |          11,          15,          19,          21,         260, ... = A049354
   4 |          75,          78,          99,         108,         114, ... = A049355
   5 |         694,         698,         714,         722,         738, ... = A049356
   6 |        8345,        8350,        8375,        8385,        8410, ... = A049357
   7 |      123717,      123723,      123759,      123771,      123807, ... = A049358
   8 |     2177399,     2177406,     2177455,     2177469,     2177518, ... = A049359
   9 |    44317196,    44317204,    44317268,    44317284,    44317348, ... = A049360
  10 |  1023456789,  1023456798,  1023456879,  1023456897,  1023456978, ...
  11 | 26432593615, 26432593625, 26432593725, 26432593745, 26432593845, ...
  ...         |                                                       \______ A378001 (main diagonal)
           A049363
T(2,4) = 12 = 1100_2 is the fourth number in base 2 containing an equal amount of zeros and ones.
T(9,5) = 44317348 = 102345867_9 is the fifth number in base 9 containing an equal amount of digits from 0 to 8.
		

Crossrefs

Cf. A049363 (first column, from n = 2), A378001 (main diagonal).

Programs

  • Mathematica
    Module[{dmax = 10, a, m}, a = Table[m = FromDigits[Join[{1, 0}, Range[2, n-1]], n] - 1; Table[While[!SameQ@@DigitCount[++m, n]]; m, dmax-n+2], {n, dmax+1, 2, -1}]; Array[Diagonal[a, # - dmax] &, dmax]]

A145100 Integers in which no more than half the digits (rounded up) are the same, for all bases up to ten.

Original entry on oeis.org

1, 2, 17, 19, 25, 38, 52, 56, 75, 76, 82, 83, 90, 92, 97, 98, 100, 102, 104, 105, 108, 113, 116, 135, 139, 141, 142, 147, 150, 153, 163, 165, 177, 178, 180, 184, 195, 197, 198, 201, 204, 209, 210, 212, 225, 226, 232, 267, 269, 275, 278, 279, 291, 293, 294, 298
Offset: 1

Views

Author

Reikku Kulon, Oct 01 2008

Keywords

Examples

			267 in bases [2, 10] is 100001011, 100220, 10023, 2032, 1123, 531, 413, 326, 267. There are five zeros out of nine digits in its binary representation and no more than half the digits in the other bases are identical.
		

Crossrefs

A031946 Numbers whose base-5 expansions have 5 distinct digits.

Original entry on oeis.org

694, 698, 714, 722, 738, 742, 894, 898, 954, 970, 978, 990, 1014, 1022, 1054, 1070, 1102, 1110, 1138, 1142, 1178, 1190, 1202, 1210, 1294, 1298, 1334, 1346, 1358, 1366, 1394, 1398, 1454, 1470, 1478, 1490, 1634, 1646, 1654, 1670, 1726, 1730, 1758, 1766
Offset: 1

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Author

Keywords

Comments

In other words, numbers in which 0,1,2,3,4 all occur in base 5.

Examples

			a(1) = 10234_5 = 694;
a(96) = 43210_5 = 2930.
		

Crossrefs

A supersequence of A049356. The first 96 (=4*4!) terms of this sequence and of A049356 are identical. a(97) = 100234_5 = 3194.

Extensions

Edited by Rick L. Shepherd, Jun 22 2003

A145101 Integers in which no digit occurs more than once more often than any other digit and not all repeated digits are identical, for all bases up to ten.

Original entry on oeis.org

1, 2, 17, 19, 25, 38, 52, 56, 75, 76, 82, 90, 92, 98, 100, 102, 104, 105, 108, 116, 141, 142, 150, 153, 177, 178, 180, 184, 195, 198, 204, 210, 212, 225, 226, 232, 294, 308, 316, 332, 395, 396, 410, 412, 420, 434, 450, 460, 481, 542, 572, 611, 689, 752, 818
Offset: 1

Views

Author

Reikku Kulon, Oct 01 2008

Keywords

Comments

Subset of A145100. The first number not in both sequences is 83.

Examples

			97 is in A145100 but not in this sequence: in base 3 it is 10121 and 1 occurs two times more often than either 0 or 2.
98 is in this sequence: in bases [2, 10] it is 1100010, 10122, 1202, 343, 242, 200, 142, 118, 98.
		

Crossrefs

A145104 Digitally fair numbers: integers n such that in all bases b = 2..10 no digit occurs more often than ceiling(d/b) times, where d is the number of digits of n in base b.

Original entry on oeis.org

1, 2, 19, 198, 25410896, 31596420, 10601629982, 10753657942, 11264883970, 11543640378, 11553029646, 11665278790, 12034384190, 12038440382, 12366849814, 12519032774, 12781964290, 12971872086, 13156400486
Offset: 1

Views

Author

Reikku Kulon, Oct 01 2008

Keywords

Comments

Presumed infinite. Next term >= 3^20.

Crossrefs

Extensions

More terms from Hagen von Eitzen, Jun 20 2009
Showing 1-5 of 5 results.