OFFSET
1,1
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..10000
EXAMPLE
a(22)=601 because 29^1 + 23^0 + 19^0 + 17^1 + 13^0 + 11^1 + 7^1 + 5^0 + 3^0 + 2^1 = 71 is prime and 601 = 1001011001_2.
MAPLE
A178344 := proc(n) local bdgs; bdgs := convert(n, base, 2) ; add( ithprime(i)^op(i, bdgs), i=1..nops(bdgs)) ; end proc:
for n from 1 to 2000 do if isprime(n) and isprime(A178344(n)) then printf("%d, ", n) ; end if; end do: # R. J. Mathar, Jun 07 2010
MATHEMATICA
Select[Prime@ Range@ 200, PrimeQ@ Total@ MapIndexed[Prime[First@ #2]^#1 &, Reverse@ IntegerDigits[#, 2]] &] (* Michael De Vlieger, Feb 19 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, May 29 2010
EXTENSIONS
229, 233, 541 inserted by R. J. Mathar, Jun 07 2010
STATUS
approved