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URL: https://oeis.org/A223888

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A223888
Composite odious numbers (A000069) having no proper odious divisors greater than 1.
1
25, 69, 81, 87, 115, 145, 213, 265, 289, 339, 355, 391, 415, 445, 477, 493, 505, 529, 565, 695, 731, 747, 789, 815, 841, 901, 985, 1041, 1047, 1077, 1119, 1149, 1207, 1219, 1315, 1341, 1347, 1383, 1401, 1411, 1437, 1465, 1509, 1513, 1527, 1537, 1555, 1585
OFFSET
1,1
COMMENTS
The sequence is obtained using Eratosthenes-like sieve for odious numbers.
LINKS
MATHEMATICA
odiousQ[n_] := OddQ@Total@IntegerDigits[n, 2]; okQ[n_] := n > 1 && odiousQ[n] && ! PrimeQ[n] && Catch[Do[If[odiousQ[d], Throw[False]], {d, Most@Rest@Divisors@n}]; True]; Select[Range@3000, okQ] (* Giovanni Resta, Mar 28 2013 *)
PROG
(PARI) isodi(n) = hammingweight(n) % 2;
noodid(n) = {fordiv(n, d, if ((d != 1) && (d < n) && isodi(d), return (0)); ); 1; }
lista(nn) = {forcomposite(n=1, nn, if (isodi(n) && noodid(n), print1(n, ", ")); ); } \\ Michel Marcus, Feb 08 2016
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vladimir Shevelev, Mar 28 2013
EXTENSIONS
a(10)-a(48) from Giovanni Resta, Mar 28 2013
STATUS
approved