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!)
 A067246 Numbers n such that phi(n) divides sigma(n+1) + sigma(n). 1
 1, 2, 6, 8, 11, 14, 22, 30, 70, 86, 102, 116, 130, 140, 154, 186, 238, 286, 390, 406, 422, 454, 459, 646, 830, 869, 1015, 1070, 1120, 1518, 1528, 1710, 1742, 1870, 2670, 2871, 3586, 3654, 4394, 5070, 5214, 6102, 6446, 6692, 7295, 7943, 8339, 9204, 10664 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..218 (* All terms up to 5 million *) MATHEMATICA Select[Range[11000], Divisible[DivisorSigma[1, #]+DivisorSigma[1, #+1], EulerPhi[ #]]&] (* Harvey P. Dale, Jul 16 2018 *) CROSSREFS Cf. A000010, A000203. Sequence in context: A285971 A079418 A298170 * A184420 A136496 A183173 Adjacent sequences:  A067243 A067244 A067245 * A067247 A067248 A067249 KEYWORD easy,nonn AUTHOR Benoit Cloitre, Feb 20 2002 EXTENSIONS First two terms prepended by Harvey P. Dale, Jul 16 2018 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 14:37 EST 2019. Contains 329999 sequences. (Running on oeis4.)