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 A322271 Smallest multiplication factors f, prime or 1, for all b (mod 24), coprime to 24, so that b*f is a nonzero square mod 8 and mod 3. 7
 1, 5, 7, 11, 13, 17, 19, 23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS See sequence A322269 for further explanations. This sequence is related to A322269(2). The sequence is periodic, repeating itself after phi(24) terms. Its largest term is 23, which is A322269(2). In order to satisfy the conditions, both f and b must be coprime to 24. The b(n) corresponding to each a(n) is A007310(n). In this case, the sequence is trivial, since each term is being multiplied by itself. The next related sequence A322272, corresponding to A322269(3), already has several nontrivial terms. LINKS EXAMPLE The 4th number coprime to 24 is 11. a(4) is 11, because 11 is the smallest prime with which we can multiply 11, so that the product (11*11 = 121) is a square mod 8 and mod 3. PROG (PARI) QresCode(n, nPrimes) = {   code = bitand(n, 7)>>1;   for (j=2, nPrimes,     x = Mod(n, prime(j));     if (issquare(x), code += (1<

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Last modified June 18 18:17 EDT 2021. Contains 345120 sequences. (Running on oeis4.)