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 A221860 Indices k such that prime(k) - k is a power of 2. 1
 1, 2, 3, 15, 39, 2119, 4189897, 5812974437 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The only primes in this sequence below primepi(10^8) are 2, 3 and 4189897. prime(5812974437) - 5812974437 = 2^37. - Giovanni Resta, Apr 10 2013 a(9) > 1.4*10^16, if it exists. - Chai Wah Wu, Apr 24 2018 LINKS Re: 2^k - prime(p) or prime(p) - 2^k ?, SeqFan mailing list, Apr 10 2013 FORMULA A000040(a(n))-a(n) = 2^floor(log[2](A000040(a(n)))) for all n>1. PROG (PARI) n=0; forprime(p=1, 10^8, n++; (t=p-n)==1<

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Last modified October 15 00:14 EDT 2019. Contains 328025 sequences. (Running on oeis4.)