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A096854 a(n) = A062402(-1+2^n). 2
1, 3, 12, 15, 72, 91, 312, 255, 1240, 1860, 4123, 5080, 26208, 34200, 93600, 65535, 334368, 416560, 1420800, 1596364, 6146800, 5949696, 20485332, 23788842, 120519630, 194016600, 358132380, 458803800, 1674738000, 2166798816, 6045990912, 4294967295, 22739738112, 37862623140 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..34.

MATHEMATICA

Table[DivisorSigma[1, EulerPhi[ -1+2^w]], {w, 1, 30}]

PROG

(PARI) a(n) = sigma(eulerphi(2^n-1)); \\ Michel Marcus, Aug 30 2019

CROSSREFS

Cf. A062401, A062402, A053287, A096853-A096856.

Sequence in context: A290593 A005392 A001196 * A013191 A009783 A192786

Adjacent sequences:  A096851 A096852 A096853 * A096855 A096856 A096857

KEYWORD

nonn

AUTHOR

Labos Elemer, Jul 19 2004

EXTENSIONS

More terms from Michel Marcus, Aug 30 2019

STATUS

approved

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Last modified December 15 15:10 EST 2019. Contains 329999 sequences. (Running on oeis4.)