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A189043
For all permutations of [1..n]: number of distinct values taken by sum(k=1..n, k^2 * pi(k) ).
0
1, 2, 6, 23, 89, 232, 437, 747, 1191, 1806, 2631, 3709, 5087, 6816
OFFSET
1,2
EXAMPLE
The permutations of 4 elements and the respective sums are
[ 1 2 3 4 ] 100
[ 1 2 4 3 ] 93
[ 1 3 2 4 ] 95
[ 1 3 4 2 ] 81
[ 1 4 2 3 ] 83
[ 1 4 3 2 ] 76
[ 2 1 3 4 ] 97
[ 2 1 4 3 ] 90
[ 2 3 1 4 ] 87
[ 2 3 4 1 ] 66
[ 2 4 1 3 ] 75
[ 2 4 3 1 ] 61
[ 3 1 2 4 ] 89
[ 3 1 4 2 ] 75 // same as [ 2 4 1 3 ]
[ 3 2 1 4 ] 84
[ 3 2 4 1 ] 63
[ 3 4 1 2 ] 60
[ 3 4 2 1 ] 53
[ 4 1 2 3 ] 74
[ 4 1 3 2 ] 67
[ 4 2 1 3 ] 69
[ 4 2 3 1 ] 55
[ 4 3 1 2 ] 57
[ 4 3 2 1 ] 50
All values except 75 are unique, so a(4) = 4!-1 = 23.
CROSSREFS
Cf. A126972 (sum k*pi(k)).
Sequence in context: A150275 A335537 A150276 * A228392 A190910 A150277
KEYWORD
nonn,more
AUTHOR
Joerg Arndt, Apr 22 2011
EXTENSIONS
Corrected terms (error pointed out by Alois P. Heinz), Joerg Arndt, Apr 28 2011.
a(14) from Alois P. Heinz, Apr 28 2011
STATUS
approved