A357379 a(n) = A357378(floor(n/2)) * A357378(n).
1, 2, 4, 6, 8, 10, 3, 9, 12, 16, 5, 15, 7, 11, 18, 21, 24, 27, 20, 28, 13, 14, 30, 33, 35, 42, 22, 44, 36, 48, 49, 56, 32, 40, 45, 54, 25, 50, 63, 70, 26, 39, 84, 98, 60, 80, 55, 66, 65, 75, 72, 78, 34, 38, 52, 64, 90, 96, 88, 104, 77, 91, 112, 120, 68, 76, 85
Offset: 0
Keywords
Examples
a(5) = A357378(floor(5/2)) * A357378(5) = A357378(2) * A357378(5) = 2 * 5 = 10.
Links
- Rémy Sigrist, Table of n, a(n) for n = 0..10000
- Rémy Sigrist, Density plot of the first 10000000 terms
- Rémy Sigrist, C program
- Index entries for sequences that are permutations of the natural numbers
Programs
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C
See Links section.
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Python
from itertools import count, islice def agen(): # generator of terms alst, disallowed = [1], {1}; yield 1 for n in count(1): ahalf, k = alst[n//2], 1 while ahalf*k in disallowed: k += 1 an = k; yield ahalf*an; alst.append(an); disallowed.add(ahalf*an) print(list(islice(agen(), 67))) # Michael S. Branicky, Sep 26 2022
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