A205807 List of values of n for which there exist block designs with n blocks.

7, 12, 13, 20, 21, 26, 30, 31, 35, 50, 56, 57, 63, 70, 72, 73, 82, 90, 91, 99, 100, 111, 117, 130, 132, 133, 143, 155, 176, 182, 183, 190, 195, 196, 208, 221, 222, 247, 255, 272, 273, 301, 304, 305, 306, 307, 324, 330, 336, 357, 371, 380, 381, 392, 407, 425, 438, 475, 484

Offset

1,1

Comments

I don't know how far it has been verified that there are no missing entries in this list.

References

Abbott, H. L.; and Hare, D. R.; The set of values of b for which there exist block designs with b blocks. Discrete Math. 290 (2005), no. 2-3, 275-282.

Links

Table of n, a(n) for n=1..59.

Crossrefs

Sequence in context: A083681 A178660 A048653 * A075696 A061120 A078835

Adjacent sequences: A205804 A205805 A205806 * A205808 A205809 A205810

Keyword

nonn

Author

N. J. A. Sloane, Jan 31 2012

Status

approved