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A366801 Arithmetic derivative without its inherited divisor applied to the Doudna sequence: a(n) = A342001(A005940(1+n)). 7
0, 1, 1, 2, 1, 5, 2, 3, 1, 7, 8, 8, 2, 7, 3, 4, 1, 9, 10, 12, 12, 31, 13, 11, 2, 9, 11, 10, 3, 9, 4, 5, 1, 13, 14, 16, 16, 41, 17, 17, 18, 59, 71, 46, 19, 41, 18, 14, 2, 11, 13, 14, 17, 37, 16, 13, 3, 11, 14, 12, 4, 11, 5, 6, 1, 15, 16, 24, 18, 61, 25, 23, 20, 87, 103, 62, 27, 55, 24, 22, 24, 113, 131, 94, 167, 247 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,4
LINKS
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A003557(n) = (n/factorback(factorint(n)[, 1]));
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A342001(n) = (A003415(n) / A003557(n));
A366801(n) = A342001(A005940(1+n));
CROSSREFS
Cf. A003415, A005940, A342001, A344026, A366802 (rgs-transform).
Cf. also A342002.
Sequence in context: A162180 A090003 A136645 * A247498 A091381 A127156
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, Oct 24 2023
STATUS
approved

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Last modified April 17 02:20 EDT 2024. Contains 371756 sequences. (Running on oeis4.)