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A168161
Primes p which are equal to the sum of the binary digits in all primes <= p.
6
3, 5, 11, 19, 23, 47, 61
OFFSET
1,1
COMMENTS
A subsequence of A168162.
FORMULA
A168161 = { prime p | p=A095375(pi(p)) }, where pi(n) = A000720(n).
MATHEMATICA
sbdQ[n_]:=Total[Flatten[IntegerDigits[#, 2]&/@Prime[Range[PrimePi[ n]]]]] == n; Select[Prime[Range[20]], sbdQ] (* Harvey P. Dale, Feb 04 2015 *)
PROG
(PARI) s=0; forprime(p=1, 9999, if(p==s+=norml2(binary(p)), print1(p, ", ")))
CROSSREFS
Sequence in context: A089439 A122516 A243899 * A217792 A284036 A172438
KEYWORD
fini,full,nonn,base
AUTHOR
M. F. Hasler, Nov 22 2009
EXTENSIONS
Cross reference added by Harvey P. Dale, Mar 26 2013
STATUS
approved