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A269861 Numbers n such that n and A048673(n) are of opposite parity. 4
4, 5, 7, 10, 12, 14, 15, 16, 17, 19, 21, 29, 30, 34, 36, 38, 40, 41, 42, 43, 44, 45, 48, 51, 52, 53, 55, 56, 57, 58, 61, 63, 64, 65, 67, 73, 77, 79, 82, 86, 87, 90, 91, 92, 100, 101, 102, 103, 106, 108, 110, 113, 114, 115, 120, 122, 123, 124, 125, 126, 127, 129, 130, 132, 134, 135, 136, 137, 140, 144, 146, 148, 149 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Union of even terms of A246261 and odd terms of A246263.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

FORMULA

Other identities. For all n >= 1:

A269862(a(n)) = n.

MATHEMATICA

f[n_] := (Times @@ Power[If[# == 1, 1, NextPrime@ #] & /@ First@ #, Last@ #] + 1)/2 &@ Transpose@ FactorInteger@ n; Select[Range@ 150, Xor[EvenQ@ f@ #, EvenQ@ #] &] (* Michael De Vlieger, Mar 17 2016 *)

PROG

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

(define A269861 (NONZERO-POS 1 1 (lambda (n) (- (A000035 n) (A000035 (A048673 n))))))

CROSSREFS

Complement: A269860.

Left inverse: A269862.

Cf. A000035, A048673, A246261, A246263.

Cf. also A270431.

Sequence in context: A287658 A039577 A013951 * A187479 A013947 A202342

Adjacent sequences:  A269858 A269859 A269860 * A269862 A269863 A269864

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 16 2016

STATUS

approved

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Last modified January 21 22:03 EST 2021. Contains 340352 sequences. (Running on oeis4.)