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A351425
If n = p_1^e_1 * ... * p_k^e_k, where p_1 < ... < p_k are primes, then a(n) is obtained by replacing the last factor p_k^e_k by (p_k + 1)^(e_k - 1); a(1) = 1.
3
1, 1, 1, 3, 1, 2, 1, 9, 4, 2, 1, 4, 1, 2, 3, 27, 1, 8, 1, 4, 3, 2, 1, 8, 6, 2, 16, 4, 1, 6, 1, 81, 3, 2, 5, 16, 1, 2, 3, 8, 1, 6, 1, 4, 9, 2, 1, 16, 8, 12, 3, 4, 1, 32, 5, 8, 3, 2, 1, 12, 1, 2, 9, 243, 5, 6, 1, 4, 3, 10, 1, 32, 1, 2, 18, 4, 7, 6, 1, 16, 64, 2
OFFSET
1,4
LINKS
MATHEMATICA
a[n_] := Module[{f = FactorInteger[n]}, n*(f[[-1, 1]] + 1)^(f[[-1, 2]] - 1)/f[[-1, 1]]^f[[-1, 2]]]; a[1] = 1; Array[a, 100]
CROSSREFS
Sequence in context: A226629 A349620 A349380 * A249580 A340147 A011086
KEYWORD
nonn
AUTHOR
Amiram Eldar and N. J. A. Sloane, Feb 11 2022
STATUS
approved