OFFSET
1,1
COMMENTS
Sequence extrapolated to n=1 using recurrence. - Andrew Howroyd, Apr 17 2018
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..200
Eric Weisstein's World of Mathematics, Prism Graph
Eric Weisstein's World of Mathematics, Total Dominating Set
Index entries for linear recurrences with constant coefficients, signature (2, -2, 3, 4, -7, 5, 0, -21, 39, -24, 21, 33, -36, 63, -33, 0, 33, -63, 36, -33, -21, 24, -39, 21, 0, -5, 7, -4, -3, 2, -2, 1).
FORMULA
G.f.: x*(2 + x^2 + 28*x^3 - 55*x^4 + 26*x^5 + 8*x^6 - 192*x^7 + 359*x^8 - 180*x^9 + 83*x^10 + 552*x^11 - 700*x^12 + 906*x^13 - 583*x^14 - 228*x^15 + 605*x^16 - 1362*x^17 + 596*x^18 - 636*x^19 - 673*x^20 + 684*x^21 - 1045*x^22 + 564*x^23 + 8*x^24 - 154*x^25 + 197*x^26 - 116*x^27 - 107*x^28 + 72*x^29 - 70*x^30 + 36*x^31)/((1 - x)*(1 + x)*(1 - 2*x - x^2 + 3*x^3 - x^4 - 2*x^5 + x^6)*(1 - 4*x + 10*x^2 - 19*x^3 + 28*x^4 - 34*x^5 + 37*x^6 - 34*x^7 + 28*x^8 - 19*x^9 + 10*x^10 - 4*x^11 + x^12)*(1 + 4*x + 10*x^2 + 19*x^3 + 28*x^4 + 34*x^5 + 37*x^6 + 34*x^7 + 28*x^8 + 19*x^9 + 10*x^10 + 4*x^11 + x^12)). - Andrew Howroyd, Apr 17 2018
MATHEMATICA
Table[3 + 3 (-1)^n + RootSum[1 - 2 # - #^2 + 3 #^3 - #^4 - 2 #^5 + #^6 &, #^n &] + RootSum[1 - 4 # + 10 #^2 - 19 #^3 + 28 #^4 - 34 #^5 + 37 #^6 - 34 #^7 + 28 #^8 - 19 #^9 + 10 #^10 - 4 #^11 + #^12 &, #^n &] + RootSum[1 + 4 # + 10 #^2 + 19 #^3 + 28 #^4 + 34 #^5 + 37 #^6 + 34 #^7 + 28 #^8 + 19 #^9 + 10 #^10 + 4 #^11 + #^12 &, #^n &], {n, 200}]
LinearRecurrence[{2, -2, 3, 4, -7, 5, 0, -21, 39, -24, 21, 33, -36,
63, -33, 0, 33, -63, 36, -33, -21, 24, -39, 21, 0, -5, 7, -4, -3,
2, -2, 1}, {2, 4, 5, 36, 27, 25, 114, 196, 437, 729, 1674, 3249,
6450, 12996, 24870, 49284, 95882, 190969, 369666, 724201, 1425261,
2802276, 5495162, 10764961, 21186827, 41602500, 81686669, 160326244, 314946266, 618516900, 1214288106, 2384368900}, 200]
CoefficientList[Series[(2 + x^2 + 28 x^3 - 55 x^4 + 26 x^5 + 8 x^6 - 192 x^7 + 359 x^8 - 180 x^9 + 83 x^10 + 552 x^11 - 700 x^12 + 906 x^13 - 583 x^14 - 228 x^15 + 605 x^16 - 1362 x^17 + 596 x^18 - 636 x^19 - 673 x^20 + 684 x^21 - 1045 x^22 + 564 x^23 + 8 x^24 - 154 x^25 + 197 x^26 - 116 x^27 - 107 x^28 + 72 x^29 - 70 x^30 + 36 x^31)/((1 - x) (1 + x) (1 - 2 x - x^2 + 3 x^3 - x^4 - 2 x^5 + x^6) (1 - 4 x + 10 x^2 - 19 x^3 + 28 x^4 - 34 x^5 + 37 x^6 - 34 x^7 + 28 x^8 - 19 x^9 + 10 x^10 - 4 x^11 + x^12) (1 + 4 x + 10 x^2 + 19 x^3 + 28 x^4 + 34 x^5 + 37 x^6 + 34 x^7 + 28 x^8 + 19 x^9 + 10 x^10 + 4 x^11 + x^12)), {x, 0, 199}], x]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Apr 17 2018
EXTENSIONS
a(1)-a(2) and terms a(10) and beyond from Andrew Howroyd, Apr 17 2018
STATUS
approved