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 1-3 of 3 results.

A346005 Successive numbers arising from the Moessner construction of the cubes on page 64 of Conway-Guy's "Book of Numbers".

Original entry on oeis.org

0, 1, 3, 3, 8, 12, 6, 27, 27, 9, 64, 48, 12, 125, 75, 15, 216, 108, 18, 343, 147, 21, 512, 192, 24, 729, 243, 27, 1000, 300, 30, 1331, 363, 33, 1728, 432, 36, 2197, 507, 39, 2744, 588, 42, 3375, 675, 45, 4096, 768, 48, 4913, 867, 51, 5832, 972, 54, 6859, 1083, 57, 8000, 1200
Offset: 0

Views

Author

N. J. A. Sloane, Jul 25 2021

Keywords

Comments

a(3*k+1) = (k+1)^3 for k >= 0.

References

  • J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, NY, 1996. Sequence can be seen in the successive circled numbers at the top of page 64.

Crossrefs

Programs

  • Maple
    f:=proc(n) if (n mod 3) = 0 then n
    elif (n mod 3) = 1 then ((n+2)/3)^3;
    else (n+1)^2/3; fi; end;
    [seq(f(n),n=0..100)];
  • Python
    def A346005(n): return n if n % 3 == 0 else ((n+2)//3)**3 if n % 3 == 1 else (n+1)**2//3 # Chai Wah Wu, Jul 25 2021

Formula

a(n) = n if n mod 3 = 0, = ((n+2)/3)^3 if n mod 3 = 1, and otherwise (n+1)^2/3.

A346007 Let b=5. If n == -i (mod b) for 0 <= i < b, then a(n) = binomial(b,i+1)*((n+i)/b)^(i+1).

Original entry on oeis.org

0, 1, 5, 10, 10, 5, 32, 80, 80, 40, 10, 243, 405, 270, 90, 15, 1024, 1280, 640, 160, 20, 3125, 3125, 1250, 250, 25, 7776, 6480, 2160, 360, 30, 16807, 12005, 3430, 490, 35, 32768, 20480, 5120, 640, 40, 59049, 32805, 7290, 810, 45, 100000, 50000, 10000, 1000, 50
Offset: 0

Views

Author

N. J. A. Sloane, Jul 25 2021

Keywords

Comments

These are the numbers that would arise if the Moessner construction on page 64 of Conway-Guy's "Book of Numbers" were extended to the fifth powers.

References

  • J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, NY, 1996. See pp. 63-64.

Crossrefs

Setting b = 2, 3, or 4 gives A346004, A346005, and A346006.

Programs

  • Maple
    f:=proc(n,b) local i;
    for i from 0 to b-1 do
    if ((n+i) mod b) = 0 then return(binomial(b,i+1)*((n+i)/b)^(i+1)); fi;
    od;
    end;
    [seq(f(n,5),n=0..80)];
  • Python
    from sympy import binomial
    def A346007(n):
        i = (5-n)%5
        return binomial(5,i+1)*((n+i)//5)**(i+1) # Chai Wah Wu, Jul 25 2021

A346595 Successive numbers arising from the Moessner construction of the sequence A010790 (n!*(n+1)!) on pages 64, 65 of Conway-Guy's "Book of Numbers".

Original entry on oeis.org

1, 2, 5, 4, 12, 40, 51, 31, 9, 144, 564, 904, 769, 376, 106, 16, 2880, 12576, 23300, 24080, 15345, 6273, 1650, 270, 25, 86400, 408960, 840216, 991276, 748530, 381065, 133848, 32523, 5370, 575, 36, 3628800, 18299520, 40691952, 52965360, 45165064, 26726896, 11323991, 3487055, 782187, 126483, 14357, 1085, 49
Offset: 1

Views

Author

N. J. A. Sloane, Jul 25 2021

Keywords

Comments

The circled numbers 5, 31, 106, 270, 575, 1085, ... in the second row of the display at the foot of page 64 are (essentially) A212523.
This sequence can also be represented as a triangle of numbers where the rows have lengths 1, 3, 5, 7, ... - Jinyuan Wang, Aug 06 2021

Examples

			As a triangle, this is:
1,
2, 5, 4,
12, 40, 51, 31, 9,
144, 564, 904, 769, 376, 106, 16,
2880, 12576, 23300, 24080, 15345, 6273, 1650, 270, 25,
86400, 408960, 840216, 991276, 748530, 381065, 133848, 32523, 5370, 575, 36,
...
		

References

  • J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, NY, 1996. Sequence can be obtained by reading the successive circled numbers in the tableau at the foot of page 64.

Crossrefs

Extensions

More terms from Jinyuan Wang, Aug 06 2021
Showing 1-3 of 3 results.