This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A297109 If n is prime(k)^e, e >= 1, then a(n) = k, otherwise 0. 2
 0, 1, 2, 1, 3, 0, 4, 1, 2, 0, 5, 0, 6, 0, 0, 1, 7, 0, 8, 0, 0, 0, 9, 0, 3, 0, 2, 0, 10, 0, 11, 1, 0, 0, 0, 0, 12, 0, 0, 0, 13, 0, 14, 0, 0, 0, 15, 0, 4, 0, 0, 0, 16, 0, 0, 0, 0, 0, 17, 0, 18, 0, 0, 1, 0, 0, 19, 0, 0, 0, 20, 0, 21, 0, 0, 0, 0, 0, 22, 0, 2, 0, 23, 0, 0, 0, 0, 0, 24, 0, 0, 0, 0, 0, 0, 0, 25, 0, 0, 0, 26, 0, 27, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA If A001221(n) = 1 [when n is in A000961], then a(n) = A055396(n) = A001511(A297108(n)), otherwise 0. PROG (PARI) A297109(n) = if(1==omega(n), primepi(factor(n)[1, 1]), 0); CROSSREFS Cf. A000720, A000961, A001221, A001511, A055396, A100995, A297108. Sequence in context: A260437 A262677 A307742 * A073312 A166514 A246024 Adjacent sequences:  A297106 A297107 A297108 * A297110 A297111 A297112 KEYWORD nonn AUTHOR Antti Karttunen, Dec 25 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 October 15 10:15 EDT 2019. Contains 328026 sequences. (Running on oeis4.)