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A027705
Primes with odd number of 1's in binary expansion such that next prime has even number of 1's.
4
2, 13, 19, 41, 47, 67, 79, 97, 109, 137, 157, 193, 251, 271, 283, 307, 313, 331, 367, 379, 397, 443, 457, 463, 499, 521, 541, 569, 587, 617, 641, 661, 677, 733, 743, 769, 787, 809, 829, 859, 877, 883, 929, 971, 1009, 1021, 1039, 1051, 1087, 1109, 1129, 1171, 1213, 1231, 1259, 1279, 1291
OFFSET
1,1
LINKS
MAPLE
N:=1000: # to get all terms in the first N primes
Res:= NULL: w:= 0: p:= 0:
for i from 1 to N+1 do
q:= nextprime(p);
v:= convert(convert(q, base, 2), `+`) mod 2;
if w = 1 and v = 0 then Res:= Res, p fi;
p:= q; w:= v;
od:
Res; # Robert Israel, Dec 29 2016
CROSSREFS
Sequence in context: A020601 A298051 A298656 * A296938 A350976 A296199
KEYWORD
nonn
EXTENSIONS
More terms from Scott Lindhurst (ScottL(AT)alumni.princeton.edu)
Offset changed by Robert Israel, Dec 29 2016
STATUS
approved