OFFSET
1,1
COMMENTS
A biquanimous number (A064544) is a number whose digits can be split into two groups with equal sums.
REFERENCES
William P. Thurston, personal communication.
William P. Thurston, Biquanimous Generating Function, math-fun mailing list, November 2001.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1660
Index entries for linear recurrences with constant coefficients, signature (17, -114, 348, -228, -1524, 3888, -216, -11046, 11382, 12012, -26544, 84, 28812, -13152, -15816, 13407, 3201, -5834, 628, 984, -288).
FORMULA
From Alois P. Heinz, Jun 12 2017: (Start)
G.f.: -x*(988416*x^33 +272448*x^32 -6983328*x^31 -2873424*x^30 +20931912*x^29 +11886288*x^28 -33545700*x^27 -25677164*x^26 +28467368*x^25 +29854804*x^24 -7032026*x^23 -11748538*x^22 -12593064*x^21 -17118040*x^20 +24399398*x^19 +29412358*x^18 -32880510*x^17 -15770937*x^16 +33016792*x^15 -4824040*x^14 -21307320*x^13 +10258240*x^12 +7474762*x^11 -5162898*x^10 -999324*x^9 +1008806*x^8 +39654*x^7 -89810*x^6 +3200*x^5 +992*x^4 +1248*x^3 -468*x^2 +90*x -9) / ((4*x-1) *(3*x-1)^2 *(2*x-1)^3 *(x+1)^7 *(x-1)^8).
a(n) = 9^n - 2 * A288550(n). (End)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
N. J. A. Sloane, Nov 03 2001
EXTENSIONS
New offset and 4 more terms from Alois P. Heinz, Jun 11 2017
STATUS
approved