A070825 -id:A070825 - cp's OEIS frontend

A003266 Product of first n nonzero Fibonacci numbers F(1), ..., F(n).

1, 1, 1, 2, 6, 30, 240, 3120, 65520, 2227680, 122522400, 10904493600, 1570247078400, 365867569267200, 137932073613734400, 84138564904377984000, 83044763560621070208000, 132622487406311849122176000, 342696507457909818131702784000

Offset: 0

N. J. A. Sloane

Equals right border of unsigned triangle A158472. - Gary W. Adamson, Mar 20 2009
Three closely related sequences are A194157 (product of first n nonzero F(2*n)), A194158 (product of first n nonzero F(2*n-1)) and A123029 (a(2*n) = A194157(n) and a(2*n-1) = A194158(n)). - Johannes W. Meijer, Aug 21 2011
a(n+1)^2 is the number of ways to tile this pyramid of height n with squares and dominoes, where vertical dominoes can only appear (if at all) in the central column. Here is a pyramid of height n=4,
       _
     ||_
   ||_||
 ||_|||_|_
|||_|||_|_|,
and here is one of the a(5)^2 = 900 possible such tilings with our given restrictions:
       _
     | |
   ||_||
 |__|_|_|_
||__|___|||. - Greg Dresden and Jiayi Liu, Aug 23 2024

			a(5) = 30 because the first 5 Fibonacci numbers are 1, 1, 2, 3, 5 and 1 * 1 * 2 * 3 * 5 = 30.
a(6) = 240 because 8 is the sixth Fibonacci number and a(5) * 8 = 240.
a(7) = 3120 because 13 is the seventh Fibonacci number and a(6) * 13 = 3120.
G.f. = 1 + x + x^2 + 2*x^3 + 6*x^4 + 30*x^5 + 240*x^6 + 3120*x^7 + ...

R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, second edition, Addison Wesley, p 597
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Alois P. Heinz, Table of n, a(n) for n = 0..99 (terms n = 1..50 from T. D. Noe)
Alfred Brousseau, Fibonacci and Related Number Theoretic Tables, Fibonacci Association, San Jose, CA, 1972, p. 74.
Spencer J. Franks, Pamela E. Harris, Kimberly Harry, Jan Kretschmann, and Megan Vance, Counting Parking Sequences and Parking Assortments Through Permutations, arXiv:2301.10830 [math.CO], 2023.
Shyam Sunder Gupta, Fabulous Fibonacci Numbers, Lucas Numbers, and Golden Ratio, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 8, 223-274.
Tipaluck Krityakierne and Thotsaporn Aek Thanatipanonda, Ansatz in a Nutshell: A Comprehensive Step-by-Step Guide to Polynomial, C-finite, Holonomic, and C^2-finite Sequences, in Applied Mathematical Analysis and Computations (SGMC 2021) Springer Proc. Math. Stat., Vol. 471. Springer, Cham, 255-297. See p. 287.
Mathematica Stack Exchange, Product of Fibonacci numbers using For/Do/While loops.
Yuri V. Matiyasevich and Richard K. Guy, A new formula for Pi, Amer. Math. Monthly 93 (1986), no. 8, 631-635. Math. Rev. 2000i:11199.
Aidan Sudbury, Arthur Sun, David Treeby, and Edward Wang, Pick-up Sticks and the Fibonacci Factorial, arXiv:2504.19911 [math.PR], 2025.
Thotsaporn Aek Thanatipanonda and Yi Zhang, Sequences: Polynomial, C-finite, Holonomic, ..., arXiv:2004.01370 [math.CO], 2020. See pp. 5-6.
Eric Weisstein's World of Mathematics, Fibonorial
Index to divisibility sequences.

Cf. A000045, A101689, A135598, A158472.
Cf. A123741 (for Fibonacci second version), A002110 (for primes), A070825 (for Lucas), A003046 (for Catalan), A126772 (for Padovan), A069777 (q-factorial numbers for sums of powers). - Johannes W. Meijer, Aug 21 2011
Cf. A176343, A238243, A238244.

a003266 n = a003266_list !! (n-1)
a003266_list = scanl1 (*) $ tail a000045_list
-- Reinhard Zumkeller, Sep 03 2013

with(combinat): A003266 := n-> mul(fibonacci(i),i=1..n): seq(A003266(n), n=0..20);

Rest[FoldList[Times,1,Fibonacci[Range[20]]]] (* Harvey P. Dale, Jul 11 2011 *)
a[ n_] := If[ n < 0, 0, Fibonorial[n]]; (* Michael Somos, Oct 23 2017 *)
Table[Round[GoldenRatio^(n(n-1)/2) QFactorial[n, GoldenRatio-2]], {n, 20}] (* Vladimir Reshetnikov, Sep 14 2016 *)

a(n)=prod(i=1,n,fibonacci(i)) \\ Charles R Greathouse IV, Jan 13 2012

from itertools import islice
def A003266_gen(): # generator of terms
    a,b,c = 1,1,1
    while True:
        yield c
        c *= a
        a, b = b, a+b
A003266_list = list(islice(A003266_gen(),20)) # Chai Wah Wu, Jan 11 2023

a(n) is asymptotic to C*phi^(n*(n+1)/2)/sqrt(5)^n where phi = (1 + sqrt(5))/2 is the golden ratio and the decimal expansion of C is given in A062073. - Benoit Cloitre, Jan 11 2003
a(n+3) = a(n+1)*a(n+2)/a(n) + a(n+2)^2/a(n+1). - Robert Israel, May 19 2014
a(0) = 1 by convention since empty products equal 1. - Michael Somos, Oct 06 2014
0 = a(n)*(+a(n+1)*a(n+3) - a(n+2)^2) + a(n+2)*(-a(n+1)^2) for all n >= 0. - Michael Somos, Oct 06 2014
Sum_{n>=1} 1/a(n) = A101689. - Amiram Eldar, Oct 27 2020
Sum_{n>=1} (-1)^(n+1)/a(n) = A135598. - Amiram Eldar, Apr 12 2021
a(n) = (2/sqrt(5))^n * Product_{j=1..n} i^j*sinh(c*j), where c = arccsch(2) - i*Pi/2. - Peter Luschny, Jul 07 2025

a(0)=1 prepended by Alois P. Heinz, Oct 12 2016

A070826 One half of product of first n primes A000040.

Original entry on oeis.org

1, 3, 15, 105, 1155, 15015, 255255, 4849845, 111546435, 3234846615, 100280245065, 3710369067405, 152125131763605, 6541380665835015, 307444891294245705, 16294579238595022365, 961380175077106319535, 58644190679703485491635, 3929160775540133527939545, 278970415063349480483707695

Offset: 1

Wolfdieter Lang, May 10 2002

Also, with offset 0, product of first n odd primes. - N. J. A. Sloane, Feb 26 2017
Identical to A002110(n)/2, n>=1.
a(n+1) is the least odd number with exactly n distinct prime divisors. - Labos Elemer, Mar 24 2003
Also, odd numbers n for which sigma(n)*phi(n)/n^2 reaches a new record low, monotonically decreasing to the lower bound 8/Pi^2. - M. F. Hasler, Jul 08 2025

Vincenzo Librandi, Table of n, a(n) for n = 1..200

Cf. A003266 (for Fibonacci), A070825 (for Lucas), A003046 (for Catalan).
Cf. also A002110, A024451, A060389, A091852, A276086, A203008 [= A003415(a(1+n))].
Range of A196529.

a:=n->mul(ithprime(j), j=2..n):seq(a(n), n=1..17); # Zerinvary Lajos, Aug 24 2008

Rest[ FoldList[ Times, 1, Prime[ Range[ 18]] ]]/2 (* Robert G. Wilson v, Feb 17 2004 *)
FoldList[Times, 1, Prime[Range[2, 18]]] (* Zak Seidov, Jan 26 2009 *)

a(n) = prod(k=2, n, prime(k)) \\ Michel Marcus, Mar 25 2017, simplified by M. F. Hasler, Jul 09 2025

from sympy import primorial
def A070826(n): return primorial(n)>>1 # Chai Wah Wu, Jul 21 2022

a(n) = A002110(n)/2.
From Antti Karttunen, Feb 06 2024: (Start)
a(1) = 1, and for n > 1, a(n) = A276086(A060389(n-1)).
a(n) = A024451(n) - 2*A203008(n-1).
(End)
a(n) = A000040(n)*a(n-1) for n > 1, a(1) = 1. - M. F. Hasler, Jul 09 2025

Formula corrected by Gary Detlefs, Dec 07 2011

A135407 Partial products of A000032 (Lucas numbers beginning at 2).

Original entry on oeis.org

2, 2, 6, 24, 168, 1848, 33264, 964656, 45338832, 3445751232, 423827401536, 84341652905664, 27158012235623808, 14149324374760003968, 11927880447922683345024, 16269628930966540082612736

Offset: 0

Jonathan Vos Post, Dec 09 2007

This is to A000032 as A003266 is to A000045. a(n) is asymptotic to C*phi^(n*(n+1)/2) where phi=(1+sqrt(5))/2 is the golden ratio and C = 1.3578784076121057013874397... (see A218490). - Corrected and extended by Vaclav Kotesovec, Oct 30 2012

			a(0) = L(0) = 2.
a(1) = L(0)*L(1) = 2*1 = 2.
a(2) = L(0)*L(1)*L(2) = 2*1*3 = 6.
a(3) = L(0)*L(1)*L(2)*L(3) = 2*1*3*4 = 24.

G. C. Greubel, Table of n, a(n) for n = 0..95

Cf. A000032, A000045, A000204, A003266, A070825, A218490.

Rest[FoldList[Times,1,LucasL[Range[0,20]]]] (* Harvey P. Dale, Aug 21 2013 *)
Table[Round[GoldenRatio^(n(n+1)/2) QPochhammer[-1, GoldenRatio-2, n+1]], {n, 0, 20}] (* Vladimir Reshetnikov, Sep 14 2016 *)

a(n) = prod(k=0, n, fibonacci(k+1)+fibonacci(k-1)); \\ Michel Marcus, Oct 13 2016

a(n) = Product_{k=0..n} A000032(k).

C = exp( Sum_{k>=1} 1/(k*(((3-sqrt(5))/2)^k-(-1)^k)) ). - Vaclav Kotesovec, Jun 08 2013

A374654 a(n) = Product_{k=0..n} L(k)+1, where L=A000032 (Lucas numbers).

Original entry on oeis.org

3, 6, 24, 120, 960, 11520, 218880, 6566400, 315187200, 24269414400, 3009407385600, 601881477120000, 194407717109760000, 101480828331294720000, 85649819111612743680000, 116912003087351395123200000, 258141702816871880432025600000

Offset: 0

Clark Kimberling, Jul 25 2024

nonn

Cf. A000032, A000142, A003266, A070825, A082480, A135407, A374655.

w[n_] := Product[LucasL[k] + 1, {k, 0, n}]
Table[w[n], {n, 0, 20}]

a(n) = Product_{k=0..n} L(k)+1, where L=A000032 (Lucas numbers).

A218490 Decimal expansion of Lucas factorial constant.

Original entry on oeis.org

1, 3, 5, 7, 8, 7, 8, 4, 0, 7, 6, 1, 2, 1, 0, 5, 7, 0, 1, 3, 8, 7, 4, 3, 9, 7, 0, 9, 7, 6, 0, 6, 0, 7, 1, 8, 5, 5, 7, 8, 6, 0, 5, 8, 6, 5, 2, 9, 5, 6, 7, 8, 7, 0, 4, 4, 9, 6, 8, 7, 8, 2, 5, 4, 3, 8, 4, 0, 7, 1, 9, 1, 1, 0, 3, 4, 8, 6, 2, 3, 3, 6, 8, 7, 7, 1, 4

Offset: 1

Vaclav Kotesovec, Oct 30 2012

The Lucas factorial constant is associated with the Lucas factorial A135407.

			1.35787840761210570138743970976060718557860586529567870449687825438407191103...

G. C. Greubel, Table of n, a(n) for n = 1..10000

Cf. A062073, A135407, A070825, A003266, A000032, A000045, A186269, A001622.

RealDigits[QPochhammer[-1, -1/GoldenRatio^2], 10, 105][[1]] (* slightly modified by Robert G. Wilson v, Dec 21 2017 *)

prodinf(j=0, 1 + ((sqrt(5) - 3)/2)^j) \\ Iain Fox, Dec 21 2017

Equals exp( Sum_{k>=1} 1/(k*(((3-sqrt(5))/2)^k-(-1)^k)) ). - Vaclav Kotesovec, Jun 08 2013
Equals Product_{k=0..infinity} (1 + (-1)^k/phi^(2*k)). - G. C. Greubel, Dec 23 2017
Equals lim_{n->oo} A135407(n)/phi^(n*(n+1)/2), where phi is the golden ratio (A001622). - Amiram Eldar, Jan 23 2022

A294373 Product of first n Bell numbers.

Original entry on oeis.org

1, 1, 2, 10, 150, 7800, 1583400, 1388641800, 5748977052000, 121573617718644000, 14099500314919737900000, 9567497928695086546803000000, 40313580569855830588349480391000000, 1114446238307803607782300144651734867000000

Offset: 0

Vaclav Kotesovec, Oct 29 2017

nonn

Robert Israel, Table of n, a(n) for n = 0..49

Cf. A000110, A003266, A070825, A003046, A058807, A058808, A342166, A342170.

B:= map(combinat:-bell, [$0..19]):
map(i -> convert(B[1..i],`*`),[$1..20]); # Robert Israel, Oct 29 2017

Table[Product[BellB[k], {k, 0, n}], {n, 0, 15}]

log(a(n)) ~ n^2 * LambertW(n)/2 * (1 - 3/(2*LambertW(n)) + 3/(2*LambertW(n)^2) + 1/(4*LambertW(n)^3)). - Vaclav Kotesovec, Feb 26 2021

A342170 Product of first n little Schröder numbers.

Original entry on oeis.org

1, 1, 3, 33, 1485, 292545, 264168135, 1130375449665, 23503896724884345, 2422053053602606867905, 1256704025339194996874320395, 3326147448057830199712191898815585, 45398150793225628820115544929795174823365, 3225056167710201318911738099365978237877235350145

Offset: 0

Vaclav Kotesovec, Mar 03 2021

nonn

Eric Weisstein's World of Mathematics, Super Catalan Number.
Wikipedia, Schroeder-Hipparchus numbers.

Cf. A001003, A003046, A003266, A070825, A294373, A342166.

b:= proc(n) option remember; `if`(n<2, 1,
      ((6*n-3)*b(n-1)-(n-2)*b(n-2))/(n+1))
    end:
a:= proc(n) a(n):=`if`(n=0, 1, a(n-1)*b(n)) end:
seq(a(n), n=0..15);  # Alois P. Heinz, Mar 03 2021

Table[Product[Hypergeometric2F1[1-k, k+2, 2, -1], {k, 1, n}], {n, 0, 15}]
FoldList[Times, 1, Table[Hypergeometric2F1[1 - n, n + 2, 2, -1], {n, 1, 15}]]

a(n) = Product_{k=1..n} A001003(k).

a(n) ~ c * (1 + sqrt(2))^(n*(n+2)) * exp(3*n/2) / (2^((7*n + 3)/4) * Pi^((2*n + 3)/4) * n^(3*n/2 + 3/2 + 9/(16*sqrt(2)))), where c = 0.89405100528141459535141257102427907468205556782800836208733677564241771912...

A186269 a(n) = Product_{k=0..n-1} A084057(k+1).

Original entry on oeis.org

1, 1, 6, 96, 5376, 946176, 544997376, 1011515129856, 6085275021213696, 118395110812733669376, 7456050498542715562622976, 1519364146391040406489059557376, 1001953802522449942301649259468947456, 2138185445843748536070796346094885374263296, 14766000790292725890315725371457440731168428261376

Offset: 0

Paul Barry, Feb 16 2011

a(n) is the determinant of the symmetric matrix (if(j<=floor((i+j)/2), 2^j*F(j+1), 2^i*F(i+1)))_{0<=i,j<=n}.

			a(2)=6 since det[1, 1, 1; 1, 2, 2; 1, 2, 8]=6.

Cf. A000032, A070825, A135407, A218490.

Table[FullSimplify[Product[(1+Sqrt[5])^k/2 + (1-Sqrt[5])^k/2,{k,0,n}]],{n,0,15}] (* Vaclav Kotesovec, Jul 11 2015 *)
Table[Product[LucasL[k]*2^(k-1),{k,0,n}],{n,0,15}] (* Vaclav Kotesovec, Jul 11 2015 *)

a(n) = Product_{k=0..n} (1+sqrt(5))^k/2+(1-sqrt(5))^k/2.
a(n) = Product_{k=0..n} Sum_{j=0..floor(k/2)} binomial(k,2*j)*5^j. [corrected by Jason Yuen, Feb 12 2025]
a(n) ~ c * (1+sqrt(5))^(n*(n+1)/2) / 2^(n+1), where c = A218490 = 1.3578784076121057013874397... is the Lucas factorial constant. - Vaclav Kotesovec, Jul 11 2015

A342166 Product of first n Fubini numbers.

Original entry on oeis.org

1, 1, 3, 39, 2925, 1582425, 7410496275, 350464600333575, 191295845123076910125, 1355763582602823185129417625, 138623522325287867599380791765497875, 224935042709004795568466587349227029537282375, 6318777956744220129890735589019782971247629409914638125

Offset: 0

Vaclav Kotesovec, Mar 03 2021

nonn

Wikipedia, Ordered Bell number

Cf. A000670, A003046, A003266, A070825, A294373, A342170.

g:= proc(n) option remember; `if`(n=0, 1,
      add(g(n-j)*binomial(n, j), j=1..n))
    end:
a:= proc(n) option remember; `if`(n=0, 1, a(n-1)*g(n)) end:
seq(a(n), n=0..15);  # Alois P. Heinz, Mar 03 2021

Table[Product[Sum[j!*StirlingS2[k, j], {j, 0, k}], {k, 1, n}], {n, 0, 12}]
Table[Product[PolyLog[-k, 1/2]/2, {k, 1, n}], {n, 0, 12}]
FoldList[Times, 1, Table[PolyLog[-n, 1/2]/2, {n, 1, 12}]]

a(n) = Product_{k=1..n} A000670(k).
a(n) ~ c * BarnesG(n+2) / (2^n * log(2)^(n*(n+3)/2)), where c = 0.960303470666951851619546415046950178638511457142008903473074598398282549...
a(n) ~ c * Pi^((n+1)/2) * n^(n^2/2 + n + 5/12) / (A * 2^((n-1)/2) * exp(3*n^2/4 + n - 1/12) * log(2)^(n*(n+3)/2)), where A is the Glaisher-Kinkelin constant A074962.

A385732 Triangle read by rows: the numerators of the Lucas triangle.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 4, 4, 1, 1, 7, 28, 7, 1, 1, 11, 77, 77, 11, 1, 1, 18, 66, 231, 66, 18, 1, 1, 29, 174, 957, 957, 174, 29, 1, 1, 47, 1363, 4089, 44979, 4089, 1363, 47, 1, 1, 76, 3572, 25897, 155382, 155382, 25897, 3572, 76, 1, 1, 123, 3116, 36613, 1061777, 19111986, 1061777, 36613, 3116, 123, 1

Offset: 0

Peter Luschny, Jul 08 2025

			Triangle begins:
  [0] 1;
  [1] 1,  1;
  [2] 1,  3,    1;
  [3] 1,  4,    4,     1;
  [4] 1,  7,   28,     7,      1;
  [5] 1, 11,   77,    77,     11,      1;
  [6] 1, 18,   66,   231,     66,     18,     1;
  [7] 1, 29,  174,   957,    957,    174,    29,    1;
  [8] 1, 47, 1363,  4089,  44979,   4089,  1363,   47,  1;
  [9] 1, 76, 3572, 25897, 155382, 155382, 25897, 3572, 76, 1;

Donald E. Knuth and Herbert S. Wilf, The Power of a Prime that Divides a Generalized Binomial Coefficient, J. Reine Angew. Math. 396 (1989), 212-219.
Edouard Lucas, Théorie des Fonctions Numériques Simplement Périodiques, American Journal of Mathematics 1 (1878), 184-240, §9.
Diana L. Wells, The Fibonacci and Lucas triangles modulo 2, Fibonacci Quart. 32, no. 2 (1994), p. 112.

Cf. A385733 (denominators), A070825 (Lucanorial), A003266 (Fibonorial), A010048 (Fibonomial).

c := arccsch(2) - I*Pi/2:
LT := (n, k) -> mul(I^j*cosh(c*j), j = k + 1..n) / mul(I^j*cosh(c*j), j = 1..n - k):
T := (n, k) -> numer(simplify(LT(n, k))): seq(seq(T(n, k), k = 0..n), n = 0..10);

T[n_, k_] := With[{c = ArcCsch[2] - I Pi/2}, Product[I^j Cosh[c j], {j, k + 1, n}] / Product[I^j Cosh[c j], {j, 1, n - k}]];
Table[Simplify[T[n, k]], {n, 0, 8}, {k, 0, n}] // Flatten // Numerator

LT(n, k) = Product_{j=k+1..n} i^j*cosh(c*j) / Product_{j=1..n-k} i^j*cosh(c*j) where c = arccsch(2) - i*Pi/2 and i is the imaginary unit. If in this formula cosh is substituted by sinh one gets the Fibonomial triangle A010048.

T(n, k) = numerator(LT(n, k)).

cp's OEIS Frontend

A003266 Product of first n nonzero Fibonacci numbers F(1), ..., F(n).

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A070826 One half of product of first n primes A000040.

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A135407 Partial products of A000032 (Lucas numbers beginning at 2).

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A374654 a(n) = Product_{k=0..n} L(k)+1, where L=A000032 (Lucas numbers).

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A218490 Decimal expansion of Lucas factorial constant.

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A294373 Product of first n Bell numbers.

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A342170 Product of first n little Schröder numbers.

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