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 A125714 Alfred Moessner's factorial triangle. 12
 1, 2, 3, 6, 11, 6, 24, 50, 35, 10, 120, 274, 225, 85, 15, 720, 1764, 1624, 735, 175, 21, 5040, 13068, 13132, 6769, 1960, 322, 28, 40320, 109584, 118124, 67284, 22449, 4536, 546, 36, 362880, 1026576, 1172700, 723680, 269325, 63273, 9450, 870, 45, 3628800 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row sums of the triangle = 1, 5, 23, 119, 719...(matching the terms 0, 0, 1, 5, 23, 119, 719...; of A033312). The name of the triangle derives from the fact that A125714(A000124(n)) = A000142(n) for n > 0. Moessner's method uses only additions to compute the factorial n!. - Peter Luschny, Jan 27 2009 REFERENCES J. H. Conway and R. K. Guy, "The Book of Numbers", Springer-Verlag, 1996, p. 64 (based on the work of Alfred Moessner). Alfred Moessner, Eine Bemerkung ueber die Potenzen der natuerlichen Zahlen. S.-B. Math.-Nat. Kl. Bayer. Akad. Wiss., 29, 1951. Oskar Perron, Beweis des Moessnerschen Satzes. S.-B. Math.-Nat. Kl. Bayer. Akad. Wiss., 31-34, 1951. LINKS Joshua Zucker, Table of n, a(n) for n = 1..66 FORMULA Starting with the natural numbers, circle each triangular number. Underneath, take partial sums of the uncircled terms and circle the terms in this row which are offset one place to the left of the circled 1, 3, 6, 10...in the first row. Repeat with analogous operations in succeeding rows. The circled terms in the infinite set become the triangle. EXAMPLE An "x" prefaced before each term will indicate the term following the x being circled. x1 2 x3 4 5 x6 7 8 9 x10 11 12 13 14 x15... __x2 6 x11 18 26 x35 46 58 71 x85... _____________x6 24 x50 96 154 x225... _________________________x24 120 x274... ___________________________________________x120... ... i.e. circle the triangular terms in row 1. In row 2, take partial sums of the uncircled terms and circle the terms offset one place to the left of the triangular terms in row 1. Continue in subsequent rows with analogous operations. The triangle consists of the infinite set of terms prefaced with the x (circled on page 64 of "The Book of Numbers".). MAPLE Contribution from Peter Luschny, Jan 27 2009: (Start) a := proc(n) local s, m, k, i; s := array(0..n); s := 1; for m from 1 to n do s[m] := 0; for k from m by - 1 to 1 do for i from 1 to k do s[i] := s[i] + s[i - 1] od; lprint(s[k]); if k = n then RETURN(s[n]) fi od; lprint("-") od end: (End) MATHEMATICA n = 10; A125714 = Reap[ ClearAll[s]; s = 1; For[m = 1, m <= n, m++, s[m] = 0; For[k = m, k >= 1, k--, For[i = 1, i <= k, i++, s[i] = s[i] + s[i-1]]; Sow[s[k]]; If[k == n, Print[n, "! = ", s[n]]; Break[]]]]][[2, 1]] (* Jean-François Alcover, Jun 29 2012, after Peter Luschny *) PROG (PARI) T(n, k)={ my( s=vector(n)); for( m=1, n, forstep( j=m, 1, -1, s++; for( i=2, j, s[i] += s[i-1])); k<0 && print(vecextract(s, Str(m"..1")))); if( k>0, s[n+1-k], vecextract(s, "-1..1"))} /* returns T[n, k], or the whole n-th row if k is not given, prints row 1...n of the triangle if k<0 */ \\ M. F. Hasler, Dec 03 2010 CROSSREFS Cf. A033312. Sequence in context: A062527 A296444 A038752 * A247953 A284091 A004038 Adjacent sequences:  A125711 A125712 A125713 * A125715 A125716 A125717 KEYWORD nonn,tabl AUTHOR Gary W. Adamson, Dec 01 2006 EXTENSIONS More terms from Joshua Zucker, Jun 17 2007 STATUS approved

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Last modified June 17 15:28 EDT 2019. Contains 324194 sequences. (Running on oeis4.)