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.

A373279 Expansion of Sum_{k>=0} x^(3^k) / (1 - 3*x^(3^k)).

Original entry on oeis.org

1, 3, 10, 27, 81, 246, 729, 2187, 6571, 19683, 59049, 177174, 531441, 1594323, 4783050, 14348907, 43046721, 129140409, 387420489, 1162261467, 3486785130, 10460353203, 31381059609, 94143181014, 282429536481, 847288609443, 2541865834900, 7625597484987
Offset: 1

Views

Author

Seiichi Manyama, May 30 2024

Keywords

Crossrefs

Programs

  • PARI
    b(n, k) = sumdiv(n, d, (gcd(d, k)==1)*(moebius(d)*k^(n/d)))/(k*n);
    a(n, k=3) = sumdiv(n, d, d*b(d, k));

Formula

G.f. A(x) satisfies A(x) = x/(1 - 3*x) + A(x^3).
If n == 0 (mod 3), a(n) = 3^n + a(n/3) otherwise a(n) = 3^n.
a(n) = Sum_{d|n} d * A046211(d).

A373280 Expansion of Sum_{k>=0} x^(4^k) / (1 - 4*x^(4^k)).

Original entry on oeis.org

1, 4, 16, 65, 256, 1024, 4096, 16388, 65536, 262144, 1048576, 4194320, 16777216, 67108864, 268435456, 1073741889, 4294967296, 17179869184, 68719476736, 274877907200, 1099511627776, 4398046511104, 17592186044416, 70368744178688, 281474976710656, 1125899906842624
Offset: 1

Views

Author

Seiichi Manyama, May 30 2024

Keywords

Crossrefs

Formula

G.f. A(x) satisfies A(x) = x/(1 - 4*x) + A(x^4).
If n == 0 (mod 4), a(n) = 4^n + a(n/4) otherwise a(n) = 4^n.

A373282 Expansion of Sum_{k>=0} x^(6^k) / (1 - 6*x^(6^k)).

Original entry on oeis.org

1, 6, 36, 216, 1296, 7777, 46656, 279936, 1679616, 10077696, 60466176, 362797062, 2176782336, 13060694016, 78364164096, 470184984576, 2821109907456, 16926659444772, 101559956668416, 609359740010496, 3656158440062976, 21936950640377856
Offset: 1

Views

Author

Seiichi Manyama, May 30 2024

Keywords

Crossrefs

Formula

G.f. A(x) satisfies A(x) = x/(1 - 6*x) + A(x^6).
If n == 0 (mod 6), a(n) = 6^n + a(n/6) otherwise a(n) = 6^n.

A373283 Expansion of Sum_{k>=0} x^(7^k) / (1 - 7*x^(7^k)).

Original entry on oeis.org

1, 7, 49, 343, 2401, 16807, 117650, 823543, 5764801, 40353607, 282475249, 1977326743, 13841287201, 96889010414, 678223072849, 4747561509943, 33232930569601, 232630513987207, 1628413597910449, 11398895185373143, 79792266297612050, 558545864083284007
Offset: 1

Views

Author

Seiichi Manyama, May 30 2024

Keywords

Crossrefs

Programs

  • PARI
    b(n, k) = sumdiv(n, d, (gcd(d, k)==1)*(moebius(d)*k^(n/d)))/(k*n);
    a(n, k=7) = sumdiv(n, d, d*b(d, k));

Formula

G.f. A(x) satisfies A(x) = x/(1 - 7*x) + A(x^7).
If n == 0 (mod 7), a(n) = 7^n + a(n/7) otherwise a(n) = 7^n.
a(n) = Sum_{d|n} d * A373277(d).
Showing 1-4 of 4 results.