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 A324825 Number of divisors d of n such that A323243(d) is odd; number of terms of A324813 larger than 1 that divide n. 6
 0, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 2, 2, 1, 1, 2, 1, 3, 3, 2, 1, 2, 1, 2, 1, 2, 1, 4, 1, 1, 2, 2, 2, 2, 1, 2, 2, 3, 1, 4, 1, 2, 2, 2, 1, 2, 1, 4, 2, 2, 1, 2, 3, 2, 2, 2, 1, 4, 1, 2, 3, 1, 2, 3, 1, 2, 2, 4, 1, 2, 1, 2, 2, 2, 2, 3, 1, 3, 1, 2, 1, 4, 2, 2, 2, 2, 1, 4, 3, 2, 2, 2, 2, 2, 1, 3, 2, 4, 1, 3, 1, 2, 4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS Inverse Möbius transform of A324823. LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = Sum_{d|n} A324823(d). a(p^k) = 1, for all primes p and exponents k >= 1. PROG (PARI) A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552 by David A. Corneth A324823(n) = if(1==n, 0, n=A156552(n); (issquare(n) || (!(n%2) && issquare(n/2)))); A324825(n) = sumdiv(n, d, A324823(d)); (PARI) A324825(n) = sumdiv(n, d, A323243(d)%2); \\ This needs code also from A323243. CROSSREFS Cf. A000961, A156552, A324813, A324823, A324826, A324827, A324830, A324831, A324832. Sequence in context: A205794 A241665 A175307 * A316557 A032436 A280274 Adjacent sequences:  A324822 A324823 A324824 * A324826 A324827 A324828 KEYWORD nonn AUTHOR Antti Karttunen, Mar 16 2019 STATUS approved

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Last modified June 19 09:23 EDT 2021. Contains 345126 sequences. (Running on oeis4.)