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 1-5 of 5 results.

A255741 Square array read by antidiagonals upwards: T(n,k), n>=1, k>=1, in which row n lists the partial sums of the n-th row of the square array of A255740.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 5, 3, 1, 1, 5, 7, 7, 4, 1, 1, 6, 9, 13, 9, 4, 1, 1, 7, 11, 21, 16, 11, 4, 1, 1, 8, 13, 31, 25, 22, 13, 4, 1, 1, 9, 15, 43, 36, 37, 28, 15, 5, 1, 1, 10, 17, 57, 49, 56, 49, 40, 17, 5, 1, 1, 11, 19, 73, 64, 79, 76, 85, 43, 19, 5, 1, 1, 12, 21, 91, 81, 106, 109, 156, 89, 49, 21, 5, 1
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Examples

			The corner of the square array with the first 15 terms of the first 12 rows looks like this:
-------------------------------------------------------------------------
A000012: 1, 1, 1,  1,  1,  1,  1,   1,   1,   1,   1,   1,   1,   1,   1
A070941: 1, 2, 3,  3,  4,  4,  4,   4,   5,   5,   5,   5,   5,   5,   5
A005408: 1, 3, 5,  7,  9, 11, 13,  15,  17,  19,  21,  23,  25,  27,  29
A151788: 1, 4, 7, 13, 16, 22, 28,  40,  43,  49,  55,  67,  73,  85,  97
A147562: 1, 5, 9, 21, 25, 37, 49,  85,  89, 101, 113, 149, 161, 197, 233
A151790: 1, 6,11, 31, 36, 56, 76, 156, 161, 181, 201, 281, 301, 381, 461
A151781: 1, 7,13, 43, 49, 79,109, 259, 265, 295, 325, 475, 505, 655, 805
A151792: 1, 8,15, 57, 64,106,148, 400, 407, 449, 491, 743, 785,1037,1289
A151793: 1, 9,17, 73, 81,137,193, 585, 593, 649, 705,1097,1153,1545,1937
A255764: 1,10,19, 91,100,172,244, 820, 829, 901, 973,1549,1621,2197,2773
A255765: 1,11,21,111,121,211,301,1111,1121,1211,1301,2111,2201,3011,3821
A255766: 1,12,23,133,144,254,364,1464,1475,1585,1695,2795,2905,4005,5105
...
		

Crossrefs

A151781 Partial sums of A151779.

Original entry on oeis.org

1, 7, 13, 43, 49, 79, 109, 259, 265, 295, 325, 475, 505, 655, 805, 1555, 1561, 1591, 1621, 1771, 1801, 1951, 2101, 2851, 2881, 3031, 3181, 3931, 4081, 4831, 5581, 9331, 9337, 9367, 9397, 9547, 9577, 9727, 9877, 10627, 10657, 10807, 10957, 11707, 11857, 12607
Offset: 1

Views

Author

N. J. A. Sloane, Jun 25 2009

Keywords

Comments

Total number of ON cells after n-th generation of cellular automaton based on Z^3 lattice in the same way that A147562 is based on the Z^2 lattice. Here each cell has six neighbors.

Crossrefs

Programs

  • Mathematica
    a[n_] := 6*5^(Total@ IntegerDigits[n - 1, 2] - 1); a[1] = 1; Accumulate@ Array[a, 46] (* Michael De Vlieger, Oct 31 2022 *)
  • PARI
    a(n)=sum(k=1,n,6*5^(hammingweight(k-1)-1)\1) \\ Charles R Greathouse IV, Sep 14 2015

A255764 Partial sums of A255743.

Original entry on oeis.org

1, 10, 19, 91, 100, 172, 244, 820, 829, 901, 973, 1549, 1621, 2197, 2773, 7381, 7390, 7462, 7534, 8110, 8182, 8758, 9334, 13942, 14014, 14590, 15166, 19774, 20350, 24958, 29566, 66430, 66439, 66511, 66583, 67159, 67231, 67807, 68383, 72991, 73063, 73639, 74215
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

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

Crossrefs

Programs

  • Mathematica
    Accumulate@ MapAt[Floor, Array[9*8^(DigitCount[# - 1, 2, 1] - 1) &, 43], 1] (* Michael De Vlieger, Nov 03 2022 *)
  • PARI
    lista(nn) = {s = 1; for (n=2, nn, print1(s, ", "); s += 9*8^(hammingweight(n-1)-1););} \\ Michel Marcus, Mar 15 2015

Extensions

More terms from Michel Marcus, Mar 15 2015

A255765 Partial sums of A255744.

Original entry on oeis.org

1, 11, 21, 111, 121, 211, 301, 1111, 1121, 1211, 1301, 2111, 2201, 3011, 3821, 11111, 11121, 11211, 11301, 12111, 12201, 13011, 13821, 21111, 21201, 22011, 22821, 30111, 30921, 38211, 45501, 111111, 111121, 111211, 111301, 112111, 112201, 113011, 113821, 121111
Offset: 1

Views

Author

Omar E. Pol, Mar 05 2015

Keywords

Comments

Also, this is a row of the square array A255741.
Is this sequence related to positive repunits? (see formula section).

Crossrefs

Programs

  • Mathematica
    Accumulate@ MapAt[Floor, Array[10*9^(DigitCount[# - 1, 2, 1] - 1) &, 40], 1] (* Michael De Vlieger, Nov 03 2022 *)
  • PARI
    lista(nn) = {s = 1; for (n=2, nn, print1(s, ", "); s += 10*9^(hammingweight(n-1)-1););} \\ Michel Marcus, Mar 15 2015
    
  • PARI
    a(n) = sum(k=1, n, if (k==1, 1, 10*9^(hammingweight(k-1)-1))); \\ Michel Marcus, Mar 15 2015

Formula

Question: a(2^k) = A002275(k+1), k >= 0. Is this true?

Extensions

More terms from Michel Marcus, Mar 15 2015

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
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