login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A270430 Numbers n such that A048673(n) and A064216(n) are of the same parity. 6
1, 2, 3, 4, 5, 8, 9, 10, 12, 13, 16, 17, 20, 25, 26, 27, 29, 30, 31, 32, 33, 34, 36, 37, 39, 40, 41, 42, 48, 49, 50, 52, 53, 58, 62, 64, 65, 68, 69, 74, 75, 77, 80, 81, 82, 85, 90, 93, 97, 98, 99, 100, 101, 102, 104, 105, 106, 108, 109, 111, 113, 114, 116, 117, 120, 121, 124, 125, 126, 128, 130, 132, 133, 136, 137, 139, 141, 144 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

See A270434 for the possible bias favoring this sequence over the complement A270431.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..17000

FORMULA

Other identities. For all n >= 1:

A270432(a(n)) = n.

MATHEMATICA

f[n_] := (Times @@ Power[If[# == 1, 1, NextPrime@ #] & /@ First@ #, Last@ #] + 1)/2 &@ Transpose@ FactorInteger@ n; g[n_] := Times @@ Power[If[# == 1, 1, NextPrime[#, -1]] & /@ First@ #, Last@ #] &@ Transpose@ FactorInteger[2 n - 1]; Select[Range@ 144, Xor[EvenQ@ f@ #, OddQ@ g@ #] &] (* Michael De Vlieger, Mar 17 2016 *)

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A270430 (ZERO-POS 1 1 (lambda (n) (- (A000035 (A048673 n)) (A000035 (A064216 n))))))

CROSSREFS

Complement: A270431.

Left inverse: A270432.

Cf. A245449 (a subsequence).

Cf. A000035, A048673, A064216, A270434.

Cf. also A269860.

Sequence in context: A032901 A260113 A005792 * A318932 A259185 A102471

Adjacent sequences:  A270427 A270428 A270429 * A270431 A270432 A270433

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 17 2016

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 18 07:01 EST 2018. Contains 317279 sequences. (Running on oeis4.)