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A092971 Row 6 of array in A288580. 7
1, 1, 2, -9, -8, -5, -36, -35, -64, 729, 640, 385, 5184, 5005, 8960, -164025, -143360, -85085, -1679616, -1616615, -2867200, 72335025, 63078400, 37182145, 967458816, 929553625, 1640038400, -52732233225, -45921075200, -26957055125, -870712934400, -835668708875, -1469474406400, 57425401982025 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

F. Smarandache, Back and Forth Factorials, Arizona State Univ., Special Collections, 1972.

LINKS

Table of n, a(n) for n=0..33.

J. Dezert, ed., Smarandacheials (1), Mathematics Magazine for Grades 1-12, No. 4, 2004.

J. Dezert, ed., Smarandacheials (2), Mathematics Magazine for Grades 1-12, No. 4, 2004.

FORMULA

a(n, k) = !n!_k = Prod_{i=0, 1, 2, .., floor(2n/k)}_{0<|n-i*k|<=n} (n-i*k) = n(n-k)(n-2k)(n-3k)... . k=6.

MAPLE

T:=proc(n, k) local i, p;

p:=1;

for i from 0 to floor(2*n/k) do

if n-k*i <> 0 then p:=p*(n-k*i) fi; od:

p;

end;

r:=k->[seq(T(n, k), n=0..60)]; r(6); # N. J. A. Sloane, Jul 03 2017

PROG

(PARI) a(n, k)=prod(j=0, (2*n)\k, if(n-k*j==0, 1, n-k*j))

CROSSREFS

Cf. A288580, A092396, A092397, A092398, A092399, A092972, A092973, A092974.

Sequence in context: A255189 A309211 A021339 * A274195 A021975 A192599

Adjacent sequences:  A092968 A092969 A092970 * A092972 A092973 A092974

KEYWORD

sign

AUTHOR

Paul D. Hanna and Amarnath Murthy, Mar 27 2004

EXTENSIONS

Entry revised by N. J. A. Sloane, Jul 03 2017

STATUS

approved

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Last modified August 12 21:10 EDT 2020. Contains 336440 sequences. (Running on oeis4.)