cp's OEIS Frontend

A377048 Antidiagonal-sums of the absolute value of the array A377046(n,k) = n-th term of k-th differences of nonsquarefree numbers (A013929).

%I A377048 #5 Oct 19 2024 21:44:20
%S A377048 4,12,13,22,28,31,39,64,85,132,395,1103,2650,5868,12297,24694,47740,
%T A377048 88731,157744,265744,418463,605929,805692,1104513,2396645,8213998,
%U A377048 21761334,50923517,110270883,225997492,444193562,844498084,1561942458,2819780451,4973173841
%N A377048 Antidiagonal-sums of the absolute value of the array A377046(n,k) = n-th term of k-th differences of nonsquarefree numbers (A013929).
%C A377048 These are the row-sums of the absolute value triangle version of A377046.
%e A377048 The third antidiagonal of A377046 is (9, 1, -3), so a(3) = 13.
%t A377048 nn=20;
%t A377048 t=Table[Take[Differences[NestList[NestWhile[#+1&, #+1,SquareFreeQ[#]&]&,4,2*nn],k],nn],{k,0,nn}];
%t A377048 Total/@Table[Abs[t[[j,i-j+1]]],{i,nn},{j,i}]
%Y A377048 The version for primes is A376681, noncomposites A376684, composites A377035.
%Y A377048 For squarefree instead of nonsquarefree numbers we have A377040.
%Y A377048 The non-absolute version is A377047.
%Y A377048 For leading column we have A377049.
%Y A377048 For first position of 0 in each row we have A377050.
%Y A377048 A000040 lists the primes, differences A001223, seconds A036263.
%Y A377048 A005117 lists the squarefree numbers.
%Y A377048 A013929 lists the nonsquarefree numbers, differences A078147, seconds A376593.
%Y A377048 A073576 counts integer partitions into squarefree numbers, factorizations A050320.
%Y A377048 Cf. A007674, A053797, A053806, A061398, A072284, A112925, A112926, A120992, A376591, A376592.
%K A377048 nonn
%O A377048 1,1
%A A377048 _Gus Wiseman_, Oct 19 2024