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A095282
Primes whose binary-expansion ends with an even number of 1's.
4
2, 3, 11, 19, 43, 47, 59, 67, 79, 83, 107, 131, 139, 163, 179, 191, 211, 227, 239, 251, 271, 283, 307, 331, 347, 367, 379, 419, 431, 443, 463, 467, 491, 499, 523, 547, 563, 571, 587, 619, 643, 659, 683, 691, 719, 739, 751, 787, 811, 827, 859
OFFSET
1,1
LINKS
MAPLE
q:= proc(n) local i, l, r; l, r:= convert(n, base, 2), 0;
for i to nops(l) while l[i]=1 do r:=r+1 od; is(r, even)
end:
select(q, [ithprime(i)$i=1..200])[]; # Alois P. Heinz, Dec 15 2019
MATHEMATICA
been1Q[n_]:=Module[{c=Split[IntegerDigits[n, 2]][[-1]]}, c[[1]]==1&&EvenQ[ Length[ c]]]; Join[{2}, Select[Prime[Range[150]], been1Q]] (* Harvey P. Dale, Dec 14 2019 *)
PROG
(PARI) is(n)=valuation(n+1, 2)%2==0 && isprime(n) \\ Charles R Greathouse IV, Oct 09 2013
CROSSREFS
Intersection of A000040 & (complement of A079523). Complement of A095283 in A000040. Cf. A027699, A095292.
Sequence in context: A111802 A213894 A294668 * A051071 A051095 A051073
KEYWORD
nonn,base,easy
AUTHOR
Antti Karttunen, Jun 04 2004
STATUS
approved