This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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