cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-6 of 6 results.

A114790 Cumulative product of quintuple factorial A085157.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 720, 10080, 241920, 8709120, 435456000, 28740096000, 4828336128000, 1506440871936000, 759246199455744000, 569434649591808000000, 601322989968949248000000
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Examples

			a(10) = 1!!!!! * 2!!!!! * 3!!!!! * 4!!!!! * 5!!!!! * 6!!!!! * 7!!!!! * 8!!!!! * 9!!!!! * 10!!!!! = 1 * 2 * 3 * 4 * 5 * 6 * 14 * 24 * 36 * 50 = 435456000 = 2^11 * 3^5 * 5^3 * 7.
		

Crossrefs

Programs

  • GAP
    b:= function(n)
        if n<1 then return 1;
        else return n*b(n-5);
        fi;
      end;
    List([0..20], n-> Product([0..n], j-> b(j)) ); # G. C. Greubel, Aug 21 2019
  • Magma
    b:= func< n | n eq 0 select 1 else (n lt 6) select n else n*Self(n-5) >;
    [(&*[b(j): j in [0..n]]): n in [0..20]]; // G. C. Greubel, Aug 21 2019
    
  • Maple
    b:= n-> `if`(n < 1, 1, n*b(n-5)); a:= n-> product(b(j), j = 0..n); seq(a(n), n = 0..20); # G. C. Greubel, Aug 21 2019
  • Mathematica
    b[n_]:= If[n<1, 1, n*b[n-5]]; a[n_]:= Product[b[j], {j,0,n}]; Table[a[n], {n,0,20}] (* G. C. Greubel, Aug 21 2019 *)
  • PARI
    b(n)=if(n<1, 1, n*b(n-5));
    vector(20, n, n--; prod(j=0,n, b(j)) ) \\ G. C. Greubel, Aug 21 2019
    
  • Sage
    @CachedFunction
    def b(n):
        if (n<1): return 1
        else: return n*b(n-5)
    [product(b(j) for j in (0..n)) for n in (0..20)] # G. C. Greubel, Aug 21 2019
    

Formula

a(n) = Product_{j=0..n} A085157(j).
a(n) = n!!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2.
a(n) = n*(n-5)!!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

A114779 Cumulative product of quadruple factorial A007662.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 1440, 30240, 967680, 43545600, 5225472000, 1207084032000, 463520268288000, 271159356948480000, 455547719673446400000, 1578472848668491776000000, 9698137182219213471744000000
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Examples

			a(10) = 1!!!! * 2!!!! * 3!!!! * 4!!!! * 5!!!! * 6!!!! * 7!!!! * 8!!!! * 9!!!! * 10!!!! = 1 * 2 * 3 * 4 * 5 * 12 * 21 * 32 * 45 * 120 = 5225472000 = 2^13 * 3^6 * 5^3 * 7.
		

Crossrefs

Formula

a(n) = Product_{j=0..n} j!!!!.
a(n) = Product_{j=0..n} A007662(j).
a(n) = n!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2.
a(n) = n*(n-4)!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

A114796 Cumulative product of sextuple factorial A085158.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 720, 5040, 80640, 2177280, 87091200, 4790016000, 344881152000, 31384184832000, 7030057402368000, 2847173247959040000, 1822190878693785600000, 1703748471578689536000000
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Examples

			a(10) = 1!6 * 2!6 * 3!6 * 4!6 * 5!6 * 6!6 * 7!6 * 8!6 * 9!6 * 10!6
= 1 * 2 * 3 * 4 * 5 * 6 * 7 * 16 * 27 * 40 = 87091200 = 2^11 * 3^5 * 5^2 * 7.
Note that a(10) + 1 = 87091201 is prime, as is a(9) + 1 = 2177281.
		

Crossrefs

Programs

  • GAP
    b:= function(n)
        if n<1 then return 1;
        else return n*b(n-6);
        fi;
      end;
    List([0..20], n-> Product([0..n], j-> b(j)) ); # G. C. Greubel, Aug 22 2019
  • Magma
    b:=func< n | n le 6 select n else n*Self(n-6) >;
    [1] cat [(&*[b(j): j in [1..n]]): n in [1..20]]; // G. C. Greubel, Aug 22 2019
    
  • Maple
    b:= n-> `if`(n<1, 1, n*b(n-5)); a:= n-> product(b(j), j = 0..n); seq(a(n), n = 0..20); # G. C. Greubel, Aug 22 2019
  • Mathematica
    b[n_]:= b[n]= If[n<1, 1, n*b[n-6]]; a[n_]:= Product[b[j], {j,0,n}];
    Table[a[n], {n, 0, 20}] (* G. C. Greubel, Aug 22 2019 *)
  • PARI
    b(n)=if(n<1, 1, n*b(n-6));
    vector(20, n, n--; prod(j=0,n, b(j)) ) \\ G. C. Greubel, Aug 22 2019
    
  • Sage
    def b(n):
        if (n<1): return 1
        else: return n*b(n-6)
    [product(b(j) for j in (0..n)) for n in (0..20)] # G. C. Greubel, Aug 22 2019
    

Formula

a(n) = Product_{j=0..n} j!!!!!!.
a(n) = Product_{j=0..n} j!6.
a(n) = Product_{j=0..n} A085158(j).
a(n) = n!!!!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2.
a(n) = n*(n-6)!!!!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2.

A114805 Cumulative sum of quintuple factorial numbers n!!!!! (A085157).

Original entry on oeis.org

1, 2, 4, 7, 11, 16, 22, 36, 60, 96, 146, 212, 380, 692, 1196, 1946, 3002, 5858, 11474, 21050, 36050, 58226, 121058, 250226, 480050, 855050, 1431626, 3128090, 6744794, 13409690, 24659690, 42533546, 96820394, 216171626, 442778090, 836528090
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Comments

a(1) = 2 is prime; a(3) = 7 is prime; a(4) = 11 is prime; and there are no more primes in the sequence. Semiprime values are: a(2) = 4 = 2^2, a(6) = 22, a(10) = 146 = 2 * 73, a(18) = 11474 = 2 * 5737, a(23) = 250226 = 2 * 125113.

Examples

			a(10) = 0!5 + 1!5 + 2!5 + 3!5 + 4!5 + 5!5 + 6!5 + 7!5 + 8!5 + 9!5 + 10!5 =
1 + 1 + 2 + 3 + 4 + 5 + 6 + 14 + 24 + 36 + 50 = 146 = 2 * 73.
		

Crossrefs

Programs

  • GAP
    b:= function(n)
        if n<1 then return 1;
        else return n*b(n-5);
        fi;
      end;
    List([0..40], n-> Sum([0..n], j-> b(j)) ); # G. C. Greubel, Aug 21 2019
  • Magma
    b:= func< n | n eq 0 select 1 else (n lt 6) select n else n*Self(n-5) >;
    [(&+[b(j): j in [0..n]]): n in [0..40]]; // G. C. Greubel, Aug 21 2019
    
  • Maple
    b:= n-> `if`(n < 1, 1, n*b(n-5)); a:= n-> sum(b(j), j = 0..n); seq(a(n), n = 0..40); # G. C. Greubel, Aug 21 2019
  • Mathematica
    f5[0]=1; f5[n_]:= f5[n]= If[n<=6, n, n f5[n-5]]; Accumulate[f5/@Range[0, 35]] (* Giovanni Resta, Jun 15 2016 *)
  • PARI
    b(n)=if(n<1, 1, n*b(n-5));
    vector(40, n, n--; sum(j=0,n, b(j)) ) \\ G. C. Greubel, Aug 21 2019
    
  • Sage
    @CachedFunction
    def b(n):
        if (n<1): return 1
        else: return n*b(n-5)
    [sum(b(j) for j in (0..n)) for n in (0..40)] # G. C. Greubel, Aug 21 2019
    

Formula

a(n) = Sum_{j=0..n} j!5.
a(n) = Sum_{j=0..n} j!!!!!.
a(n) = Sum_{j=0..n} A085157(j).

A108895 Partial sums of quadruple factorial numbers n!!!! (A007662).

Original entry on oeis.org

1, 2, 4, 7, 11, 16, 28, 49, 81, 126, 246, 477, 861, 1446, 3126, 6591, 12735, 22680, 52920, 118755, 241635, 450480, 1115760, 2629965, 5579085, 10800210, 28097490, 68981025, 151556385, 302969010, 821887410, 2089276995, 4731688515
Offset: 0

Views

Author

Jonathan Vos Post, Feb 08 2006

Keywords

Comments

Quadruple factorial numbers n!!!! = n*(n-4)!!!!, 0!!!! = 1!!!! = 1, 2!!!! = 2, 3!!!! = 3. The cumulative sum a(n) is prime for n = 1, 3, 4 and never again, as all values from a(8) = 81 are multiples of 3. The cumulative sum a(n) is semiprime for n = 2, 7 and never again, as all values from a(16) are divisible by both 3 and 5.

Examples

			a(31) = 1 + 1 + 2 + 3 + 4 + 5 + 12 + 21 + 32 + 45 + 120 + 231 + 384 + 585 + 1680 + 3465 + 6144 + 9945 + 30240 + 65835 + 122880 + 208845 + 665280 + 1514205 + 2949120 + 5221125 + 17297280 + 40883535 + 82575360 + 151412625 + 518918400 + 1267389585 = 2089276995 = 3 * 5 * 13 * 337 * 31793.
		

References

  • J. Spanier and K. B. Oldham, An Atlas of Functions, Hemisphere, NY, 1987, p. 23.

Crossrefs

Programs

  • Mathematica
    NFactorialM[n_Integer, m_Integer] := Block[{k = n, p = Max[1, n]}, While[k > m, k -= m; p *= k]; p]; Table[ Sum[ NFactorialM[i, 4], {i, 0, n}], {n, 0, 33}] (* Robert G. Wilson v, Feb 21 2006 *)

Formula

a(n) = Sum_{i=0..n} i!!!!.
a(n) = Sum_{i=0..n} A007662(i).

A114778 Cumulative product of triple factorial A007661.

Original entry on oeis.org

1, 1, 2, 6, 24, 240, 4320, 120960, 9676800, 1567641600, 438939648000, 386266890240000, 750902834626560000, 2733286318040678400000, 33674087438261157888000000, 981936389699695364014080000000
Offset: 0

Views

Author

Jonathan Vos Post, Feb 18 2006

Keywords

Comments

This is the product analog of what for sums is A114347.

Examples

			a(10) = 1!!! * 2!!! * 3!!! * 4!!! * 5!!! * 6!!! * 7!!! * 8!!! * 9!!! * 10!!!
= 1 * 2 * 3 * 4 * 10 * 18 * 28 * 80 * 162 * 280 = 438939648000 = 2^15 * 3^7 * 5^3 * 7^2.
		

Crossrefs

Formula

a(n) = Product_{j=0..n} j!!!. a(n) = Product_{j=0..n} A007661(j). a(n) = n!!! * a(n-1) where a(0) = 1, a(1) = 1 and n >= 2. a(n) = n*(n-3)!!! * a(n-1) where a(0) = 1, a(1) = 1, a(2) = 2 and n >= 3.
Showing 1-6 of 6 results.