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A178563 Primes p such that A178344(p) is also prime. 1
3, 11, 37, 47, 59, 131, 149, 151, 157, 163, 181, 191, 193, 197, 229, 233, 239, 251, 523, 541, 547, 557, 569, 599, 601, 613, 617, 631, 643, 653, 661, 677, 701, 727, 751, 761, 769, 787, 809, 823, 839, 883, 937, 941, 947, 953, 967, 971, 1021 (list; graph; refs; listen; history; text; internal format)
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

Sequence in context: A119211 A119235 A119233 * A069358 A108544 A095088

Adjacent sequences:  A178560 A178561 A178562 * A178564 A178565 A178566

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, May 29 2010

EXTENSIONS

229, 233, 541 inserted by R. J. Mathar, Jun 07 2010

STATUS

approved

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Last modified August 9 02:14 EDT 2020. Contains 336310 sequences. (Running on oeis4.)