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 1-2 of 2 results.

A127255 Partial sums of A127252.

Original entry on oeis.org

1, 0, 1, 2, 1, 2, 3, 2, 3, 4, 5, 4, 5, 4, 5, 6, 5, 6, 7, 6, 7, 6, 7, 8, 9, 8, 9, 10, 9, 10, 11, 10, 11, 12, 13, 12, 13, 12, 13, 14, 15, 14, 15, 16, 15, 16, 17, 16, 17, 16, 17, 18, 17, 18, 19, 18, 19, 20, 21, 20, 21, 20, 21, 22, 21, 22, 23, 22, 23, 22, 23, 24, 25
Offset: 0

Views

Author

Paul Barry, Jan 10 2007

Keywords

Crossrefs

Cf. A127252.

Programs

  • Mathematica
    Accumulate[Table[If[EvenQ[IntegerExponent[n, 2]] && OddQ[DigitCount[n, 2, 1]], -1, 1], {n, 0, 100}]] (* Amiram Eldar, Aug 04 2023 *)

Extensions

More terms from Amiram Eldar, Aug 04 2023

A127251 Inverse of number triangle A127249.

Original entry on oeis.org

1, -2, 1, 2, -2, 1, 0, 0, 0, 1, 0, 0, 0, -2, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, -2, 1, 0, 0, 0, 0, 0, 0, 2, -2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 0

Views

Author

Paul Barry, Jan 10 2007

Keywords

Examples

			Triangle begins:
  1;
  -2, 1;
  2, -2, 1;
  0, 0, 0, 1;
  0, 0, 0, -2, 1;
  0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 0, 0, -2, 1;
  0, 0, 0, 0, 0, 0, 2, -2, 1;
  0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1;
  ...
		

Crossrefs

Product of A127248 and A127244.
Row sums are A127252.
Cf. A127249.

Programs

  • Mathematica
    T1[n_, k_] := SeriesCoefficient[(1 - ThueMorse[1 + k]*x)*x^k, {x, 0, n}]; (* A127248 *)
    T2[n_, k_] := (-1)^(n-k) * Product[ThueMorse[i], {i, k+1, n}]; (* A127244 *)
    T[n_, k_] := Sum[T2[n, j]*T1[j, k], {j, 0, n}];
    Table[T[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* Amiram Eldar, Aug 04 2023 *)

Extensions

More terms from Amiram Eldar, Aug 04 2023
Showing 1-2 of 2 results.