This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A285710 Numbers n for which A000010(n) = A285699(n); positions of zeros in A285709. 6
 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 14, 16, 17, 19, 21, 23, 25, 27, 28, 29, 31, 32, 37, 41, 43, 47, 49, 53, 59, 61, 62, 64, 67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 109, 113, 121, 124, 125, 127, 128, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 237 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS After a(1) = 1, also numbers n such that A051953(n) = A079277(n). LINKS Antti Karttunen, Table of n, a(n) for n = 1..6672 MATHEMATICA Flatten@ Position[#, 0] &@ Table[EulerPhi@ n - (n - If[n <= 2, n - 1, Module[{k = n - 2, e = Floor@ Log2@ n}, While[PowerMod[n, e, k] != 0, k--]; k]]), {n, 240}] (* Michael De Vlieger, Apr 26 2017 *) PROG (Scheme, with Antti Karttunen's IntSeq-library) (define A285710 (ZERO-POS 1 1 A285709)) (Python) from sympy import divisors, totient from sympy.ntheory.factor_ import core def a007947(n): return max(list(filter(lambda i: core(i) == i, divisors(n)))) def a079277(n):     k=n - 1     while True:         if a007947(k*n) == a007947(n): return k         else: k-=1 def a285699(n): return 1 if n<2 else n - a079277(n) print [n for n in xrange(1, 301) if totient(n) == a285699(n)] # Indranil Ghosh, Apr 26 2017 CROSSREFS Positions of zeros in A285709. Cf. A000010, A051953, A079277, A208815, A285699. Cf. A000961 (a subsequence). Sequence in context: A129562 A191841 A050741 * A133810 A176615 A291453 Adjacent sequences:  A285707 A285708 A285709 * A285711 A285712 A285713 KEYWORD nonn AUTHOR Antti Karttunen, Apr 26 2017 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.