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 1-4 of 4 results.

A255766 Partial sums of A255745.

Original entry on oeis.org

1, 12, 23, 133, 144, 254, 364, 1464, 1475, 1585, 1695, 2795, 2905, 4005, 5105, 16105, 16116, 16226, 16336, 17436, 17546, 18646, 19746, 30746, 30856, 31956, 33056, 44056, 45156, 56156, 67156, 177156, 177167, 177277, 177387, 178487, 178597, 179697, 180797, 191797
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

Also, this is a row of the square array A255741.

Crossrefs

Programs

  • PARI
    a(n) = sum(k=1, n, if (k==1, 1, 11*10^(hammingweight(k-1)-1)));

Extensions

More terms from Michel Marcus, Mar 19 2015

A255740 Square array read by antidiagonals upwards: T(n,1) = 1; for k > 1, T(n,k) = (n-1)*(n-2)^(A000120(k-1)-1) with n >= 1.

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 2, 1, 0, 1, 3, 2, 0, 0, 1, 4, 3, 2, 1, 0, 1, 5, 4, 6, 2, 0, 0, 1, 6, 5, 12, 3, 2, 0, 0, 1, 7, 6, 20, 4, 6, 2, 0, 0, 1, 8, 7, 30, 5, 12, 6, 2, 1, 0, 1, 9, 8, 42, 6, 20, 12, 12, 2, 0, 0, 1, 10, 9, 56, 7, 30, 20, 36, 3, 2, 0, 0, 1, 11, 10, 72, 8, 42, 30, 80, 4, 6, 2, 0, 0, 1, 12, 11, 90, 9, 56, 42, 150, 5, 12, 6, 2, 0, 0
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

The partial sums of row n give the n-th row of the square array A255741.

Examples

			The corner of the square array with the first 16 terms of the first 12 rows looks like this:
-------------------------------------------------------------------------
A000007: 1, 0, 0,  0, 0,  0,  0,   0, 0,  0,  0,   0,  0,   0,   0,    0
A255738: 1, 1, 1,  0, 1,  0,  0,   0  1,  0,  0,   0,  0,   0,   0,    0
A040000: 1, 2, 2,  2, 2,  2,  2,   2, 2,  2,  2,   2,  2,   2,   2,    2
A151787: 1, 3, 3,  6, 3,  6,  6,  12, 3,  6,  6,  12,  6,  12,  12,   24
A147582: 1, 4, 4, 12, 4, 12, 12,  36, 4, 12, 12,  36, 12,  36,  36,  108
A151789: 1, 5, 5, 20, 5, 20, 20,  80, 5, 20, 20,  80, 20,  80,  80,  320
A151779: 1, 6, 6, 30, 6, 30, 30, 150, 6, 30, 30, 150, 30, 150, 150,  750
A151791: 1, 7, 7, 42, 7, 42, 42, 252, 7, 42, 42, 252, 42, 252, 252, 1512
A151782: 1, 8, 8, 56, 8, 56, 56, 392, 8, 56, 56, 392, 56, 392, 392, 2744
A255743: 1, 9, 9, 72, 9, 72, 72, 576, 9, 72, 72, 576, 72, 576, 576, 4608
A255744: 1,10,10, 90,10, 90, 90, 810,10, 90, 90, 810, 90, 810, 810, 7290
A255745: 1,11,11,110,11,110,110,1100,11,110,110,1100,110,1100,1100,11000
...
		

Crossrefs

Column 1 is A000012.
Columns 2^k+1, for k >=0: A011477.
Columns 4, 6, 7, 10, 11, 13...: 0 together with A002378.

Programs

  • PARI
    tabl(nn) = {for (n=1, nn, for (k=1, nn, if (k==1, x = 1, x= (n-1)*(n-2)^(hammingweight(k-1)-1)); print1(x, ", ");); print(););} \\ Michel Marcus, Mar 15 2015

Formula

T(n,1) = 1; for k > 1, T(n,k) = (n-1)*(n-2)^(A000120(k-1)-1) with n >= 1.

A255743 a(1) = 1; for n > 1, a(n) = 9*8^{A000120(n-1)-1}.

Original entry on oeis.org

1, 9, 9, 72, 9, 72, 72, 576, 9, 72, 72, 576, 72, 576, 576, 4608, 9, 72, 72, 576, 72, 576, 576, 4608, 72, 576, 576, 4608, 576, 4608, 4608, 36864, 9, 72, 72, 576, 72, 576, 576, 4608, 72, 576, 576, 4608, 576, 4608, 4608, 36864, 72, 576, 576, 4608, 576, 4608, 4608
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

Also, this is a row of the square array A255740.
Partial sums give A255764.

Examples

			Written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins:
   1;
   9;
   9, 72;
   9, 72, 72, 576;
   9, 72, 72, 576, 72, 576, 576, 4608;
   ...
		

Crossrefs

Programs

  • Mathematica
    MapAt[Floor, Array[9*8^(DigitCount[# - 1, 2, 1] - 1) &, 55], 1] (* Michael De Vlieger, Nov 03 2022 *)
  • PARI
    a(n) = if (n==1, 1, 9*8^(hammingweight(n-1)-1)); \\ Michel Marcus, Mar 15 2015
    
  • Python
    # Python 3.10+
    def A255743(n): return 1 if n == 1 else 9*(1<<((n-1).bit_count()-1)*3) # Chai Wah Wu, Nov 15 2022

Extensions

More terms from Michel Marcus, Mar 15 2015

A255744 a(1) = 1; for n > 1, a(n) = 10*9^(A000120(n-1)-1).

Original entry on oeis.org

1, 10, 10, 90, 10, 90, 90, 810, 10, 90, 90, 810, 90, 810, 810, 7290, 10, 90, 90, 810, 90, 810, 810, 7290, 90, 810, 810, 7290, 810, 7290, 7290, 65610, 10, 90, 90, 810, 90, 810, 810, 7290, 90, 810, 810, 7290, 810, 7290, 7290, 65610, 90, 810, 810, 7290, 810, 7290
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

Also, this is a row of the square array A255740.
Partial sums give A255765.

Examples

			Also, written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins:
1;
10;
10, 90;
10, 90, 90, 810;
10, 90, 90, 810, 90, 810, 810, 7290;
...
		

Crossrefs

Programs

  • Mathematica
    MapAt[Floor, Array[10*9^(DigitCount[# - 1, 2, 1] - 1) &, 54], 1] (* Michael De Vlieger, Nov 03 2022 *)
  • PARI
    a(n) = if (n==1, 1, 10*9^(hammingweight(n-1)-1)); \\ Michel Marcus, Mar 15 2015

Extensions

More terms from Michel Marcus, Mar 15 2015
Showing 1-4 of 4 results.