cp's OEIS Frontend

A343191 Squiggle Dot Numbers: numbers generated in a similar way to those in A010790 except that every prime number is divided instead of multiplied. The result is then rounded to the closest integer.

%I A343191 #34 Dec 23 2024 09:51:43
%S A343191 1,1,0,0,0,0,0,0,8,677,616,671,620,668,140180,33643245,31664230,
%T A343191 33526832,31762262,33433960,14042263246,6487525619781,6205459288487,
%U A343191 6475261866247,3885157119748074,2525352127836247843,1772797193741045985945,1340234678468230765374557,1294019689555533152775435
%N A343191 Squiggle Dot Numbers: numbers generated in a similar way to those in A010790 except that every prime number is divided instead of multiplied. The result is then rounded to the closest integer.
%F A343191 a(n) = round(n^(2*A010051(n)-1)*(A000142(n)/A034386(n)^2)^2).
%e A343191               / 1*4*6*8*9*10*9*8*6*4*1 \
%e A343191 a(10) = round | ---------------------- |             = 677;
%e A343191               \    2*3*5*7 * 7*5*3*2   /
%e A343191               / 1*4*6*8*9*10*10*9*8*6*4*1 \
%e A343191 a(11) = round | ------------------------- |          = 616;
%e A343191               \     2*3*5*7*11*7*5*3*2    /
%e A343191               / 1*4*6*8*9*10*12*10*9*8*6*4*1 \
%e A343191 a(12) = round | ----------------------------- |      = 671;
%e A343191               \    2*3*5*7*11*11*7*5*3*2     /
%e A343191               / 1*4*6*8*9*10*12*12*10*9*8*6*4*1 \
%e A343191 a(13) = round | ------------------------------- |    = 620.
%e A343191               \    2*3*5*7*11*13*11*7*5*3*2     /
%o A343191 (PARI) sqdot(n)={my(s=if(isprime(n),1/n,n));for(k=2,n-1,my(kk=k*k);if(isprime(k),s/=kk,s*=kk));round(s)};
%o A343191 for(k=1,29,print1(sqdot(k),", ")) \\ _Hugo Pfoertner_, Apr 07 2021
%Y A343191 Cf. A010790.
%K A343191 nonn,easy
%O A343191 1,9
%A A343191 _Brian Labore_, Apr 07 2021