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 A252670 a(n) is exponential digital index of prime(n). 1
 22, 0, 11, 4, 2, 0, 0, 2, 1, 0, 0, 2, 2, 0, 0, 0, 0, 2, 0, 2, 2, 0, 0, 0, 0, 2, 0, 0, 2, 1, 2, 1, 0, 0, 0, 0, 0, 2, 0, 0, 1, 2, 0, 0, 0, 0, 2, 0, 0, 1, 0, 0, 3, 1, 0, 0, 0, 2, 0, 0, 0, 0, 2, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 1, 0, 1, 0, 0, 5, 0, 2, 0, 0, 1, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For the definition of the exponential digital index of a prime p (EDI(p)), see comment in A252668. Is 22 the maximal term? Is 11 the second maximal term? LINKS FORMULA a(n)=0, iff n is not in A251964; a(n)=1, iff n is in A251964, but is not A252280; a(n)=2, iff n is in A251964 & A252980, but is not in A252981, a(n)>=3, iff n is in A251964 & A252980 & A252281. PROG (PARI) s(k, pp) = my(sd = sumdigits(pp^k)); sd/2^valuation(sd, 2); f(n, pp) = {my(p = prime(n), k = 1); while ((sk=s(k, pp)) % p, k++); if (sk == p, k, 0); } a(n) = {my(pp=prime(n), j=3); while (f(j, pp), j++); j - 3; } \\ Michel Marcus, Dec 09 2018 CROSSREFS Cf. A000040, A251964, A252280, A252281, A252282, A252283, A252666, A252668. Sequence in context: A023922 A022064 A225343 * A297813 A156462 A040488 Adjacent sequences: A252667 A252668 A252669 * A252671 A252672 A252673 KEYWORD nonn,base AUTHOR Vladimir Shevelev, Dec 20 2014 EXTENSIONS More terms from Michel Marcus, Dec 09 2018 STATUS approved

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Last modified March 27 07:19 EDT 2023. Contains 361554 sequences. (Running on oeis4.)