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A032284 "DIK" (bracelet, indistinct, unlabeled) transform of 3,3,3,3... 1
3, 9, 22, 57, 150, 444, 1362, 4497, 15338, 54018, 193722, 705392, 2593398, 9612144, 35840622, 134318097, 505486878, 1909275084, 7234415562, 27489389850, 104718539638, 399828796884, 1529767891122, 5864087533072, 22518048468582, 86607787095594, 333600173734122 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..200

C. G. Bower, Transforms (2)

Index entries for sequences related to bracelets

FORMULA

G.f.: (3*x/((1-x)*(1-2*x)) + Sum_{d>0} phi(d)*log((1-x^d)/(1-4*x^d))/d)/2. - Andrew Howroyd, Jun 20 2018

PROG

(PARI) seq(n)={Vec(3*x/((1-x)*(1-2*x)) + sum(d=1, n, eulerphi(d)/d*log((1-x^d)/(1-4*x^d) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018

CROSSREFS

Cf. A032283.

Sequence in context: A054442 A192663 A114697 * A296582 A203454 A197666

Adjacent sequences:  A032281 A032282 A032283 * A032285 A032286 A032287

KEYWORD

nonn

AUTHOR

Christian G. Bower

EXTENSIONS

Terms a(24) and beyond from Andrew Howroyd, Jun 20 2018

STATUS

approved

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Last modified August 18 22:17 EDT 2018. Contains 313840 sequences. (Running on oeis4.)