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A265110 Partial row products of table A027746, prime factors with repetition. 3

%I #12 Apr 29 2017 04:30:57

%S 1,2,3,2,4,5,2,6,7,2,4,8,3,9,2,10,11,2,4,12,13,2,14,3,15,2,4,8,16,17,

%T 2,6,18,19,2,4,20,3,21,2,22,23,2,4,8,24,5,25,2,26,3,9,27,2,4,28,29,2,

%U 6,30,31,2,4,8,16,32,3,33,2,34,5,35,2,4,12,36

%N Partial row products of table A027746, prime factors with repetition.

%C T(n,1) = A020639(n); T(n,A001222(n)) = n.

%H Reinhard Zumkeller, <a href="/A265110/b265110.txt">Rows n = 1..1000 of triangle, flattened</a>

%F T(n,k) = product(A027747(n,k): k = 1 .. A001221(n)).

%e . n | T(n,*) | A027746(n,*)

%e . ----+----------------+----------------

%e . 1 | 1 | 1

%e . 2 | 2 | 2

%e . 3 | 3 | 3

%e . 4 | 2, 4 | 2, 2

%e . 5 | 5 | 5

%e . 6 | 2, 6 | 2, 3

%e . 7 | 7 | 7

%e . 8 | 2, 4, 8 | 2, 2, 2

%e . 9 | 3, 9 | 3, 3

%e . 10 | 2, 10 | 2, 5

%e . 11 | 11 | 11

%e . 12 | 2, 4, 12 | 2, 2, 3

%e . 13 | 13 | 13

%e . 14 | 2, 14 | 2, 7

%e . 15 | 3, 15 | 3, 5

%e . 16 | 2, 4, 8, 16 | 2, 2, 2, 2

%e . 17 | 17 | 17

%e . 18 | 2, 6, 18 | 2, 3, 3

%e . 19 | 19 | 19

%e . 20 | 2, 4, 20 | 2, 2, 5

%t Table[FoldList[Times, Flatten[FactorInteger[n] /. {p_, e_} /; e > 0 :> ConstantArray[p, e]]], {n, 37}] // Flatten (* _Michael De Vlieger_, Apr 28 2017 *)

%o (Haskell)

%o a265110 n k = a265110_tabf !! (n-1) !! (k-1)

%o a265110_row n = a265110_tabf !! (n-1)

%o a265110_tabf = map (scanl1 (*)) a027746_tabf

%Y Cf. A027746, A175943, A001222 (row lengths), A020639.

%K nonn,tabf

%O 1,2

%A _Reinhard Zumkeller_, Dec 01 2015

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Last modified August 29 19:44 EDT 2024. Contains 375518 sequences. (Running on oeis4.)