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A269861 Numbers n such that n and A048673(n) are of opposite parity. 5
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
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. also A270431.
Sequence in context: A039577 A370861 A013951 * A187479 A013947 A202342
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 16 2016
STATUS
approved

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Last modified March 29 00:26 EDT 2024. Contains 371264 sequences. (Running on oeis4.)