A375924 Number A(n,k) of partitions of [n] such that the element sum of each block is one more than a multiple of k; square array A(n,k), n>=0, k>=0, read by antidiagonals.
1, 1, 1, 1, 1, 0, 1, 1, 2, 0, 1, 1, 1, 5, 0, 1, 1, 0, 2, 15, 0, 1, 1, 0, 0, 4, 52, 0, 1, 1, 0, 1, 1, 10, 203, 0, 1, 1, 0, 1, 2, 3, 28, 877, 0, 1, 1, 0, 0, 0, 3, 9, 96, 4140, 0, 1, 1, 0, 0, 0, 0, 1, 17, 320, 21147, 0, 1, 1, 0, 0, 0, 1, 1, 8, 108, 1436, 115975, 0
Offset: 0
Examples
A(5,2) = 10: 12345, 124|3|5, 12|34|5, 12|3|45, 14|23|5, 1|234|5, 1|23|45, 14|25|3, 1|245|3, 1|25|34. A(6,3) = 9: 136|25|4, 13|256|4, 13|25|46, 16|235|4, 1|2356|4, 1|235|46, 16|25|34, 1|256|34, 1|25|346. A(7,4) = 8: 14|23|5|67, 1|234|5|67, 1|23|45|67, 1|23|467|5, 14|27|36|5, 1|247|36|5, 1|27|346|5, 1|27|36|45. A(8,5) = 1: 12345678. A(8,8) = 4: 18|27|36|45, 1|278|36|45, 1|27|368|45, 1|27|36|458. A(9,6) = 87: 123469|58|7, 12349|568|7, 12349|58|67, 123568|49|7, ..., 1|25|346789, 16|289|3457, 1|2689|3457, 1|289|34567. A(9,8) = 5: 18|27|36|45|9, 1|278|36|45|9, 1|27|368|45|9, 1|27|36|458|9, 1|27|36|45|89. A(9,10) = 1: 1|29|38|47|56. Square array A(n,k) begins: 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, ... 0, 5, 2, 0, 1, 1, 0, 0, 0, 0, 0, ... 0, 15, 4, 1, 2, 0, 0, 0, 1, 1, 0, ... 0, 52, 10, 3, 3, 0, 1, 1, 0, 0, 0, ... 0, 203, 28, 9, 1, 1, 3, 0, 0, 1, 1, ... 0, 877, 96, 17, 8, 15, 4, 0, 1, 1, 0, ... 0, 4140, 320, 108, 32, 1, 0, 1, 4, 0, 0, ... 0, 21147, 1436, 324, 51, 10, 87, 72, 5, 0, 1, ... 0, 115975, 5556, 1409, 621, 50, 1, 0, 0, 1, 5, ...
Links
- Alois P. Heinz, Antidiagonals n = 0..40, flattened
- Wikipedia, Partition of a set