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A317291 Numbers k not in A239019 such that A177894(k) = 0. 1
0, 1001, 1012, 1023, 1034, 1045, 1056, 1067, 1078, 1089, 1100, 1122, 1133, 1144, 1155, 1166, 1177, 1188, 1199, 1210, 1221, 1232, 1243, 1254, 1265, 1276, 1287, 1298, 1320, 1331, 1342, 1353, 1364, 1375, 1386, 1397, 1430, 1441, 1452, 1463, 1474, 1485, 1496 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Of course A177894(A239019(n)) = 0 because the corresponding circular matrices each contains at least two identical rows or columns. This sequence gives the other numbers.
A four-digit number abcd is in this sequence if and only if a + c = b + d and (a != c or b != d).
LINKS
Eric Weisstein's World of Mathematics, Circulant Matrix.
Wikipedia, Circulant matrix.
EXAMPLE
2178 is a term because the value of the following determinant is 0, although the determinant itself contains no identical rows or columns:
| 2 1 7 8 |
| 1 7 8 2 |
| 7 8 2 1 |
| 8 2 1 7 |
PROG
(PARI) for(n=0, 1500, if(!n ||(n&!A177894(n)&&!A239019(n)), print1(n, ", "))) \\ See A177894 and A239019 for their programs
CROSSREFS
Sequence in context: A262859 A044881 A291269 * A362921 A241946 A100846
KEYWORD
nonn,base
AUTHOR
Jianing Song, Jan 21 2019
STATUS
approved

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)