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A377048
Antidiagonal-sums of the absolute value of the array A377046(n,k) = n-th term of k-th differences of nonsquarefree numbers (A013929).
9
4, 12, 13, 22, 28, 31, 39, 64, 85, 132, 395, 1103, 2650, 5868, 12297, 24694, 47740, 88731, 157744, 265744, 418463, 605929, 805692, 1104513, 2396645, 8213998, 21761334, 50923517, 110270883, 225997492, 444193562, 844498084, 1561942458, 2819780451, 4973173841
OFFSET
1,1
COMMENTS
These are the row-sums of the absolute value triangle version of A377046.
EXAMPLE
The third antidiagonal of A377046 is (9, 1, -3), so a(3) = 13.
MATHEMATICA
nn=20;
t=Table[Take[Differences[NestList[NestWhile[#+1&, #+1, SquareFreeQ[#]&]&, 4, 2*nn], k], nn], {k, 0, nn}];
Total/@Table[Abs[t[[j, i-j+1]]], {i, nn}, {j, i}]
CROSSREFS
The version for primes is A376681, noncomposites A376684, composites A377035.
For squarefree instead of nonsquarefree numbers we have A377040.
The non-absolute version is A377047.
For leading column we have A377049.
For first position of 0 in each row we have A377050.
A000040 lists the primes, differences A001223, seconds A036263.
A005117 lists the squarefree numbers.
A013929 lists the nonsquarefree numbers, differences A078147, seconds A376593.
A073576 counts integer partitions into squarefree numbers, factorizations A050320.
Sequence in context: A087760 A237279 A032498 * A144613 A031330 A052339
KEYWORD
nonn,new
AUTHOR
Gus Wiseman, Oct 19 2024
STATUS
approved