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A079786
Triangle read by rows in which the n-th row begins with n and contains tau(n) numbers. The r-th term from right is the largest number < n with r divisors, for 1<= r <= tau(n).
1
1, 2, 1, 3, 1, 4, 3, 1, 5, 1, 6, 4, 5, 1, 7, 1, 8, 4, 7, 1, 9, 7, 1, 10, 9, 7, 1, 11, 1, 12, 10, 9, 11, 1, 13, 1, 14, 9, 13, 1, 15, 9, 13, 1, 16, 15, 9, 13, 1, 17, 1, 18, 16, 15, 9, 17, 1, 19, 1, 20, 16, 15, 9, 19, 1, 21, 9, 19, 1, 22, 9, 19, 1, 23, 1, 24, 20, 16, 22, 9, 23, 1, 25, 23, 1, 26, 25
OFFSET
1,2
COMMENTS
The number of terms in the n-th row = tau(n).
EXAMPLE
1
2 1
3 1
4 3 1
5 1
6 4 5 1
7 1
8 4 7 1
9 7 1
...
PROG
(PARI) print(1, ", "); for(i=2, 50, v=[1]; for(j=2, sigma(i, 0), forstep(k=i, 1, -1, if(sigma(k, 0)==j, v=concat(v, k); break))); forstep(l=length(v), 1, -1, print1(v[l], ", ")); print()) \\ Lambert Herrgesell (zero815(AT)googlemail.com), Mar 13 2006
CROSSREFS
Cf. A079787.
Sequence in context: A354185 A322994 A256147 * A032451 A214494 A088445
KEYWORD
nonn,tabf
AUTHOR
Amarnath Murthy, Feb 03 2003
EXTENSIONS
More terms from Lambert Herrgesell (zero815(AT)googlemail.com), Mar 13 2006
Offset corrected by Andrew Howroyd, Sep 29 2024
STATUS
approved