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A080267 a(n) = Sum_{d divides n} d*2^(n-n/d). 3
1, 5, 13, 41, 81, 257, 449, 1313, 2497, 6465, 11265, 33665, 53249, 143617, 269313, 672257, 1114113, 3159041, 4980737, 13568001, 23904257, 57675777, 96468993, 275980289, 424673281, 1090535425, 1963720705, 4823482369, 7784628225 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

FORMULA

G.f. Sum( k*2^(k-1)*x^k/(1-2^(k-1)*x^k), k=1..infinity). - N. J. A. Sloane (njas(AT)research.att.com), Jun 04 2003

MAPLE

oo := 40; s1 := add( k*2^(k-1)*x^k/(1-2^(k-1)*x^k), k=1..oo): s2 := series(s1, x, oo-1): s3 := seriestolist(%): A080267 := n->s3[n+1];

CROSSREFS

Cf. A075900.

Sequence in context: A103729 A027862 A100210 * A034735 A200150 A046717

Adjacent sequences:  A080264 A080265 A080266 * A080268 A080269 A080270

KEYWORD

nonn

AUTHOR

Vladeta Jovovic (vladeta(AT)eunet.rs), Feb 11 2003

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Last modified February 16 11:51 EST 2012. Contains 205908 sequences.