A378141 For any n > 0, a(n) is the least positive integer such that the XOR difference triangle with bottom row (a(1), ..., a(n)) has distinct values.

1, 2, 4, 8, 16, 32, 9, 18, 64, 128, 39, 75, 156, 256, 76, 137, 259

Offset

1,2

Comments

By necessity, all terms are distinct.

This sequence is finite; see A380112 for the infinite variant.

Links

Table of n, a(n) for n=1..17.

Rémy Sigrist, PARI program

Example

The XOR difference triangle for the whole sequence is:
                                    258
                                  465 211
                                171 378 425
                              367 452 190 279
                            205 418 102 216 463
                          163 110 460 426 370 189
                         98 193 175 355 201 443 262
                      195 161  96 207 428 357 222 472
                     65 130  35  67 140 288  69 155 323
                   36 101 231 196 135  11 299 366 501 182
                 28  56  93 186 126 249 242 473 183 322 500
               51  47  23  74 240 142 119 133 348 491 169 349
             17  34  13  26  80 160  46  89 220 384 107 194 415
           15  30  60  49  43 123 219 245 172 112 496 411 345 198
         5   10  20  40  25  50  73 146 103 203 187 331 208 393 335
       3   6   12  24  48  41  27  82 192 167 108 215 412 332 197 394
     1   2   4   8   16  32  9   18  64 128  39  75 156 256  76 137 259

Prog

(PARI) \\ See Links section.

Crossrefs

Cf. A099884, A380112.

Sequence in context: A364628 A328753 A119990 * A380112 A036128 A073477

Adjacent sequences: A378138 A378139 A378140 * A378142 A378143 A378144

Keyword

nonn,base,fini,full

Author

Rémy Sigrist, Jan 09 2025

Status

approved