[seqfan] Trivial array of powers
Richard J. Mathar
mathar at mpia-hd.mpg.de
Wed Dec 9 11:05:35 CET 2015
Here is a another boring array apparently well hidden in the OEIS:
1 2 3 4 5 6 7 8
0 2 6 12 20 30 42 56
0 2 12 36 80 150 252 392
0 2 24 108 320 750 1512 2744
0 2 48 324 1280 3750 9072 19208
0 2 96 972 5120 18750 54432 134456
0 2 192 2916 20480 93750 326592 941192
0 2 384 8748 81920 468750 1959552 6588344
defined by T(n,l)= l*(l-1)^(n-1), giving the number of n-letter
words drawn from an alphabet of l letters, and no adjacent letters the same.
Rows n>=1. Columns l>=1. Closely related to A051129.
(Actualy: the aray of n-leter words; "let(t)er" and "ar(r)ay" are not in the
dictionary admit(t)ed by this definition.)
Richard
More information about the SeqFan
mailing list