This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A295879 Multiplicative with a(p) = 1, a(p^e) = prime(e-1) if e > 1. 2
 1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 5, 1, 2, 1, 2, 1, 1, 1, 3, 2, 1, 3, 2, 1, 1, 1, 7, 1, 1, 1, 4, 1, 1, 1, 3, 1, 1, 1, 2, 2, 1, 1, 5, 2, 2, 1, 2, 1, 3, 1, 3, 1, 1, 1, 2, 1, 1, 2, 11, 1, 1, 1, 2, 1, 1, 1, 6, 1, 1, 2, 2, 1, 1, 1, 5, 5, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 2, 1, 1, 1, 7, 1, 2, 2, 4, 1, 1, 1, 3, 1, 1, 1, 6, 1, 1, 1, 5, 1, 1, 1, 2, 2, 1, 1, 3, 2, 1, 1, 2, 3, 2, 1, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS This sequence can be used as a filter. It matches at least to the following sequences related to the counting of various non-unitary prime divisors: For all i, j:   a(i) = a(j) => A056170(i) = A056170(j), as A056170(n) = A001222(a(n)).   a(i) = a(j) => A162641(i) = A162641(j).   a(i) = a(j) => A295659(i) = A295659(j).   a(i) = a(j) => A295662(i) = A295662(j).   a(i) = a(j) => A295883(i) = A295883(j), as A295883(n) = A007949(a(n)).   a(i) = a(j) => A295884(i) = A295884(j). LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(1) = 1; for n>1, if n = Product prime(i)^e(i), then a(n) = Product A008578(e(i)). a(n) = A064989(A181819(n)). MATHEMATICA Array[Apply[Times, FactorInteger[#] /. {p_, e_} /; p > 0 :> Which[p == 1, 1, e == 1, 1, True, Prime[e - 1]]] &, 128] (* Michael De Vlieger, Nov 29 2017 *) PROG (Scheme, with memoization-macro definec) (definec (A295879 n) (cond ((= 1 n) 1) (else (* (A008578 (A067029 n)) (A295879 (A028234 n)))))) CROSSREFS Cf. A008578, A064989, A181819. Cf. also A293515, A294875, A294895, A294897, A295878. Differs from A000688 for the first time at n=128, where a(128) = 13, while A000688(128) = 15. Sequence in context: A227350 A107345 A000688 * A322453 A319786 A321271 Adjacent sequences:  A295876 A295877 A295878 * A295880 A295881 A295882 KEYWORD nonn,mult AUTHOR Antti Karttunen, Nov 29 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 11 07:07 EST 2018. Contains 318049 sequences. (Running on oeis4.)