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A307408
a(n) = (A001222(n) - 1)*A001221(n) + 2.
5
2, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 6, 2, 4, 4, 5, 2, 6, 2, 6, 4, 4, 2, 8, 3, 4, 4, 6, 2, 8, 2, 6, 4, 4, 4, 8, 2, 4, 4, 8, 2, 8, 2, 6, 6, 4, 2, 10, 3, 6, 4, 6, 2, 8, 4, 8, 4, 4, 2, 11, 2, 4, 6, 7, 4, 8, 2, 6, 4, 8, 2, 10, 2, 4, 6, 6, 4, 8, 2, 10, 5, 4, 2, 11, 4, 4, 4, 8, 2, 11, 4, 6, 4, 4, 4, 12, 2, 6, 6, 8, 2, 8, 2, 8
OFFSET
1,1
COMMENTS
a(n) appears to differ from A000005 at n = 1 and when n is a term of A320632. Verified up to n=3000.
See also Charlie Neder's May 14 2019 comment in A307409.
FORMULA
a(n) = (A001222(n) - 1)*A001221(n) + 2.
a(n) = binomial(A001222(n) - 1, 1)*binomial(A001221(n), 1) + 2.
a(n) = A307409(n) + 2.
MATHEMATICA
a[n_] := (PrimeOmega[n] - 1)*PrimeNu[n] + 2;
Table[a[n], {n, 1, 104}]
PROG
(PARI) A307408(n) = 2+((bigomega(n)-1)*omega(n)); \\ Antti Karttunen, Nov 17 2019
CROSSREFS
Two more than A307409.
Sequence in context: A036013 A256587 A249616 * A233539 A317223 A321576
KEYWORD
nonn
AUTHOR
Mats Granvik, Apr 07 2019
STATUS
approved