# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a306093 Showing 1-1 of 1 %I A306093 #17 Oct 16 2018 23:09:22 %S A306093 1,3,21,102,525,2334,11100,47496,210756,886080,3759114,15378051, %T A306093 63685767,255417357,1030081827,4078689249,16150234665,62991117084, %U A306093 245948154087,947944122906,3653360869998,13946363438502,53149517598207,200994216333375,759191650345380 %N A306093 Number of plane partitions of n where parts are colored in 3 colors. %C A306093 a(0) = 1 corresponds to the empty sum, in which all terms are colored in one among three given colors, since there is no term at all. %H A306093 Alois P. Heinz, Table of n, a(n) for n = 0..50 %F A306093 a(n) = Sum_{k=1..n} A091298(n,k)*3^k. %e A306093 For n = 1, there is only the partition [1], which can be colored in any of the three colors, whence a(1) = 3. %e A306093 For n = 2, there are the partitions [2], [1,1] and [1;1]. Adding colors, this yields a(2) = 3 + 9 + 9 = 21 distinct possibilities. %o A306093 (PARI) a(n)=sum(k=1,n,A091298(n,k)*3^k,!n) %Y A306093 Cf. A091298, A208447. %Y A306093 Column 3 of A306100 and A306101. See A306099 for column 2, A306094 .. A306096 for columns 4 .. 6. %K A306093 nonn %O A306093 0,2 %A A306093 _M. F. Hasler_, Sep 22 2018 %E A306093 a(12) corrected and a(13)-a(24) added by _Alois P. Heinz_, Sep 24 2018 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE