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A235331 Numbers with odious squares. 3
1, 2, 4, 5, 7, 8, 9, 10, 11, 14, 16, 17, 18, 19, 20, 22, 23, 25, 28, 29, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41, 43, 44, 46, 49, 50, 51, 55, 56, 58, 59, 62, 64, 65, 66, 67, 68, 70, 71, 72, 75, 76, 77, 78, 79, 80, 82, 85, 86, 87, 88, 89, 91, 92, 95, 97, 98, 100 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numbers that are sqrt(odious squares).

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..2600

FORMULA

a(n) = sqrt(A235001(n)).

EXAMPLE

1 = sqrt(A235001(1)) = sqrt(1).

2 = sqrt(A235001(2)) = sqrt(4).

4 = sqrt(A235001(3)) = sqrt(16).

5 = sqrt(A235001(4)) = sqrt(25).

MATHEMATICA

Select[Range[200], OddQ[DigitCount[#^2, 2][[1]]] &] (* Vincenzo Librandi, Jan 31 2018 *)

PROG

(MAGMA) [n : n in [0..130] |IsOdd(&+Intseq(n^2, 2))]; // Vincenzo Librandi, Jan 31 2018

(PARI) isok(n) = (hammingweight(n^2) % 2) == 1; \\ Michel Marcus, Jan 31 2018

CROSSREFS

Cf. A235001, A194991.

Sequence in context: A039099 A215069 A035257 * A175969 A183573 A187895

Adjacent sequences:  A235328 A235329 A235330 * A235332 A235333 A235334

KEYWORD

nonn,easy

AUTHOR

Gerasimov Sergey, Jan 06 2014

STATUS

approved

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Last modified July 14 18:26 EDT 2020. Contains 335729 sequences. (Running on oeis4.)