[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A229516
Number of n X 3 0..2 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1) X 4 0..2 array without adjacent equal elements in the latter.
1
17, 129, 775, 4193, 23059, 124431, 680991, 3698901, 20206283, 110016923, 600355767, 3271586963, 17843919361, 97271016715, 530426786593, 2891844158939, 15768179521109, 85971178631931, 468755026926535, 2555792909067505
OFFSET
1,1
COMMENTS
Column 3 of A229521.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) + 25*a(n-2) - 20*a(n-3) - 102*a(n-4) + 151*a(n-5) - 18*a(n-6) + 5*a(n-7) + 231*a(n-8) + 419*a(n-9) - 945*a(n-10) - 472*a(n-11) + 2170*a(n-12) + 574*a(n-13) + 1442*a(n-14) - 3690*a(n-15) + 1136*a(n-16) - 1022*a(n-17) - 1356*a(n-18) + 1988*a(n-19) - 911*a(n-20) - 417*a(n-21) + 603*a(n-22) - 5369*a(n-23) + 8946*a(n-24) - 6852*a(n-25) + 3802*a(n-26) + 1216*a(n-27) - 4313*a(n-28) + 4655*a(n-29) - 3958*a(n-30) + 2476*a(n-31) + 1330*a(n-32) - 2970*a(n-33) + 2524*a(n-34) - 1231*a(n-35) - 456*a(n-36) + 800*a(n-37) - 387*a(n-38) + 142*a(n-39) - 29*a(n-40) - 44*a(n-41) + 36*a(n-42) - 12*a(n-43) + 4*a(n-44) for n > 45.
EXAMPLE
Some solutions for n=3:
0 1 1 1 0 1 1 2 1 1 1 2 1 1 1 2 0 2 1 1 1
2 0 1 1 1 1 2 0 2 1 1 1 1 1 0 0 1 0 1 1 1
0 2 1 2 1 1 1 2 1 0 1 0 2 0 2 1 1 1 0 1 2
CROSSREFS
Cf. A229521.
Sequence in context: A336186 A159563 A341397 * A352114 A279637 A179818
KEYWORD
nonn
AUTHOR
R. H. Hardin, Sep 25 2013
STATUS
approved