OFFSET
1,2
COMMENTS
Numbers with only one nonzero digit when written in factorial base. - Franklin T. Adams-Watters, Nov 28 2011
When the numbers denote finite permutations (as row numbers of A055089) these are the circular shifts to the right within an interval. The subsequence A001563 denotes the circular shifts that start with the first element. Compare A211370 for circular shifts to the left. - Tilman Piesk, Apr 29 2017
LINKS
Reinhard Zumkeller, Rows n=1..150 of triangle, flattened
Tilman Piesk, Circular shifts to the right (Arrays of permutations).
FORMULA
T(n,k) = A000142(A002024(n)) * A002260(n,k) = A002024(n)! * A002260(n,k) - Antti Karttunen, Jul 02 2013
Sum_{n>=1} 1/a(n) = e * (gamma - Ei(-1)) = A347952. - Amiram Eldar, Oct 13 2024
EXAMPLE
Table begins
1;
2, 4;
6, 12, 18;
24, 48, 72, 96; ...
MATHEMATICA
T[n_, k_] := n!*k; Flatten[Table[T[n, k], {n, 9}, {k, n}]] (* Jean-François Alcover, Apr 22 2011 *)
PROG
(Haskell)
a051683 n k = a051683_tabl !! (n-1) !! (k-1)
a051683_row n = a051683_tabl !! (n-1)
a051683_tabl = map fst $ iterate f ([1], 2) where
f (row, n) = (row' ++ [head row' + last row'], n + 1) where
row' = map (* n) row
-- Reinhard Zumkeller, Mar 09 2012
(Scheme): (define (A051683 n) (* (A000142 (A002024 n)) (A002260 n))) -- Antti Karttunen, Jul 02 2013
(Magma) [[Factorial(n)*k: k in [1..n]]: n in [1..15]]; // Vincenzo Librandi, Jun 15 2015
(PARI) for(n=1, 10, for(k=1, n, print1(n!*k, ", "))) \\ G. C. Greubel, Mar 27 2018
CROSSREFS
KEYWORD
AUTHOR
Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de)
STATUS
approved