This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A153734 #15 Feb 16 2021 05:57:14 %S A153734 1,1,1,1,1,2,1,1,2,3,3,1,1,4,5,5,6,4,1,1,9,5,5,5,10,16,9,10,5,1,1,6, %T A153734 14,14,35,15,21,21,14,20,35,14,15,6,1,1,7,20,14,21,28,56,64,70,42,14, %U A153734 90,35,70,56,28,35,64,20,21,7,1 %N A153734 Triangle T(n,k): T(n,k) gives the A153452(m_k) such that A056239(m_k) = n, [1<=k<=A000041(n)], sorted by m_k, read by rows. Sequence A060240 is this sequence's permutation. %C A153734 Lengths of rows are 1, 1, 2, 3, 5, 7, 11, 15, 22, 30,.... (A000041). Row sums give A000085. %H A153734 Alois P. Heinz, <a href="/A153734/b153734.txt">Rows n = 0..26, flattened</a> %e A153734 For n=4, A056239(7) = A056239(9) = A056239(10) = A056239(12) = A056239(16) = 4. Hence T(4,k) = A153452(m_k) = (1,2,3,3,1), where 1<=k<=5, m_k = 7,9,10,12,16. %e A153734 Triangle T(n,k) begins: %e A153734 1; %e A153734 1; %e A153734 1, 1; %e A153734 1, 2, 1; %e A153734 1, 2, 3, 3, 1; %e A153734 1, 4, 5, 5, 6, 4, 1; %e A153734 1, 9, 5, 5, 5, 10, 16, 9, 10, 5, 1; %e A153734 ... %p A153734 with(numtheory): %p A153734 g:= proc(n) option remember; `if`(n=1, 1, %p A153734 add(g(n/q*`if`(q=2, 1, prevprime(q))), q=factorset(n))) %p A153734 end: %p A153734 b:= proc(n, i) option remember; `if`(n=0 or i<2, [2^n], %p A153734 [seq(map(p->p*ithprime(i)^j, b(n-i*j, i-1))[], j=0..n/i)]) %p A153734 end: %p A153734 T:= n-> map(g, sort(b(n, n)))[]: %p A153734 seq(T(n), n=0..10); # _Alois P. Heinz_, Aug 09 2012 %t A153734 g[n_] := g[n] = If[n == 1, 1, Sum[g[n/q*If[q == 2, 1, NextPrime[q, -1]]], {q, FactorInteger[n][[All, 1]]}]]; %t A153734 b[n_, i_] := b[n, i] = If[n == 0 || i < 2, {2^n}, Flatten[Table[Map[ #*Prime[i]^j&, b[n - i*j, i - 1]], {j, 0, n/i}]]]; %t A153734 T[n_] := g /@ Sort[b[n, n]]; %t A153734 T /@ Range[0, 10] // Flatten (* _Jean-François Alcover_, Feb 16 2021, after _Alois P. Heinz_ *) %Y A153734 Cf. A067924, A215366. %K A153734 easy,nonn,look,tabf %O A153734 0,6 %A A153734 _Naohiro Nomoto_, Dec 31 2008