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A061318
Column 3 of A061314.
4
0, 4, 40, 304, 1720, 7480, 26404, 79240, 209304, 499140, 1095160, 2242504, 4332640, 7966504, 14036260, 23829040, 39156304, 62512740, 97268904, 147902080, 220270120, 321933304, 462529540, 654208504, 912130600, 1255036900, 1705896504, 2292638040, 3048972304, 4015313320
OFFSET
0,2
FORMULA
a(n) = A061316(n) + A006007(n)^2 = 4*A061319(n).
G.f. -4*x*(1+x+22*x^2+22*x^3+22*x^4+x^5+x^6)/(x-1)^9. - R. J. Mathar, Aug 11 2012
MATHEMATICA
CoefficientList[Series[-4x (1+x+22x^2+22x^3+22x^4+x^5+x^6)/(x-1)^9, {x, 0, 30}], x] (* or *) LinearRecurrence[{9, -36, 84, -126, 126, -84, 36, -9, 1}, {0, 4, 40, 304, 1720, 7480, 26404, 79240, 209304}, 30] (* Harvey P. Dale, Jul 04 2023 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Henry Bottomley, Apr 24 2001
EXTENSIONS
a(25)-a(29) from Stefano Spezia, Aug 31 2023
STATUS
approved