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 A265885 a(n) = n IMPL prime(n), where IMPL is the bitwise logical implication. 3
 2, 3, 5, 7, 11, 13, 25, 23, 23, 29, 31, 55, 59, 59, 63, 63, 63, 61, 111, 111, 107, 111, 123, 127, 103, 101, 103, 107, 111, 113, 127, 223, 223, 223, 221, 223, 223, 251, 255, 255, 247, 245, 255, 211, 215, 215, 211, 223, 239, 237, 237, 239, 251, 251, 457, 455 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Implies FORMULA a(n) = A265705(A000040(n),n). EXAMPLE .   prime(25)=97 | 1100001 .             25 |   11001 .   -------------+-------- .     25 IMPL 97 | 1100111 -> a(25) = 103 . MAPLE a:= n-> Bits[Implies](n, ithprime(n)): seq(a(n), n=1..56);  # Alois P. Heinz, Sep 24 2021 MATHEMATICA IMPL[n_, k_] := If[n == 0, 0, BitOr[2^Length[IntegerDigits[k, 2]]-1-n, k]]; a[n_] := n ~IMPL~ Prime[n]; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Sep 25 2021, after David A. Corneth's code in A265705 *) PROG (Haskell) a265885 n = n `bimpl` a000040 n where    bimpl 0 0 = 0    bimpl p q = 2 * bimpl p' q' + if u <= v then 1 else 0                where (p', u) = divMod p 2; (q', v) = divMod q 2 (Julia) using IntegerSequences [Bits("IMP", n, p) for (n, p) in enumerate(Primes(1, 263))] |> println  # Peter Luschny, Sep 25 2021 (PARI) a(n) = bitor((2<

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Last modified May 29 07:24 EDT 2022. Contains 354122 sequences. (Running on oeis4.)