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 A324573 a(1) = 0; for n > 1, a(n) = sigma(A048675(n)). 7
 0, 1, 3, 3, 7, 4, 15, 4, 7, 6, 31, 7, 63, 13, 12, 7, 127, 6, 255, 12, 18, 18, 511, 6, 15, 48, 12, 18, 1023, 8, 2047, 6, 39, 84, 28, 12, 4095, 176, 54, 8, 8191, 12, 16383, 39, 15, 258, 32767, 12, 31, 13, 144, 54, 65535, 8, 42, 12, 252, 800, 131071, 15, 262143, 1302, 28, 12, 91, 20, 524287, 144, 528, 14, 1048575, 8, 2097151, 2736, 18 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 (based on Hans Havermann's prime signature data) FORMULA a(1) = 0; for n > 1, a(n) = A000203(A048675(n)). PROG (PARI) A048675(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; }; A324573(n) = if(1==n, 0, sigma(A048675(n))); CROSSREFS Cf. A000203, A048675, A324574, A324575. Cf. also A277892, A322812, A323243. Sequence in context: A085870 A336510 A332463 * A096633 A175482 A318261 Adjacent sequences:  A324570 A324571 A324572 * A324574 A324575 A324576 KEYWORD nonn AUTHOR Antti Karttunen, Mar 08 2019 STATUS approved

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Last modified July 29 09:28 EDT 2021. Contains 346344 sequences. (Running on oeis4.)