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A333993 Square spiral on a 2D square lattice, one term per cell, starting at the origin with 0; the integers forming a square of size k X k, for all k = 1, 2, 3, ..., add up to a number that does not contain the digit 1. 0
0, 2, 3, 4, 5, 20, 6, 7, 23, 8, 9, 22, 24, 25, 200, 26, 27, 28, 29, 203, 30, 33, 32, 202, 2000, 34, 35, 36, 205, 37, 38, 204, 39, 42, 2002, 40, 43, 90, 59, 84, 46, 2023, 44, 206, 53, 82, 48, 220, 284, 45, 57, 74, 207, 47, 85, 2244, 49, 52, 50, 76, 2043, 273, 20007, 436, 54, 55, 56, 58, 62, 60, 96 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is the lexicographically earliest sequence of distinct nonnegative terms with this property. Computed in memory of Michaƫl Falcoz, August 2, 1986 - August 20, 2020.

LINKS

Table of n, a(n) for n=1..71.

EXAMPLE

No integer in the spiral contains "1"; the integers forming any 2 X 2 square add up to a number without "1"; the integers forming any 3 X 3 square add up to a number without "1", etc.

The 5 X 5 square visible here (without the leg 34-35) is made of 25 terms summing up to 2968, a result that doesn't use the digit 1.

.

     30--33--32-202-2000-34

      |                   |

    203   6---7--23---8  35

      |   |           |   .

     29  20   0---2   9   .

      |   |       |   |   .

     28   5---4---3  22

      |               |

     27--26--200-25--24

.

CROSSREFS

Cf. A337115.

Sequence in context: A295317 A165646 A261639 * A342617 A329579 A024635

Adjacent sequences:  A333990 A333991 A333992 * A333994 A333995 A333996

KEYWORD

base,nonn

AUTHOR

Eric Angelini and Jean-Marc Falcoz, Sep 04 2020

STATUS

approved

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Last modified October 25 20:31 EDT 2021. Contains 348256 sequences. (Running on oeis4.)