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”).

A290273
Number of minimal dominating sets in the n-pan graph.
1
2, 2, 3, 5, 7, 8, 13, 18, 25, 34, 49, 69, 95, 134, 188, 264, 368, 517, 725, 1015, 1422, 1993, 2794, 3913, 5484, 7685, 10769, 15089, 21144, 29630, 41518, 58178, 81523, 114237, 160075, 224308, 314317, 440442, 617177, 864830, 1211861, 1698141, 2379551, 3334390, 4672376
OFFSET
1,1
COMMENTS
Extended to a(1)-a(2) using the recurrence.
LINKS
Eric Weisstein's World of Mathematics, Minimal Dominating Set
Eric Weisstein's World of Mathematics, Pan Graph
FORMULA
a(n) = a(n-2) + a(n-3) + a(n-4) - a(n-6).
G.f.: x*(2 + 2*x + x^2 + x^3 - 2*x^5)/(1 - x^2 - x^3 - x^4 + x^6).
MATHEMATICA
Table[-RootSum[1 - #^2 - #^3 - #^4 + #^6 &, -9 #^n + 33 #^(n + 1) - 23 #^(n + 2) - 45 #^(n + 3) - 38 #^(n + 4) + #^(n + 5) &]/229, {n, 20}]
LinearRecurrence[{0, 1, 1, 1, 0, -1}, {2, 2, 3, 5, 7, 8}, 50]
CoefficientList[Series[(2 + 2 x + x^2 + x^3 - 2 x^5)/(1 - x^2 - x^3 - x^4 + x^6), {x, 0, 20}], x]
CROSSREFS
Sequence in context: A079953 A133393 A126881 * A125505 A357381 A061565
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jul 25 2017
STATUS
approved