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.

A372956 G.f. A(x) satisfies A(x)^5 = A(x^5) / (1 - 5*x)^5 with A(0)=1.

Original entry on oeis.org

1, 5, 25, 125, 625, 3126, 15630, 78150, 390750, 1953750, 9768753, 48843765, 244218825, 1221094125, 6105470625, 30527353136, 152636765680, 763183828400, 3815919142000, 19079595710000, 95397978550044, 476989892750220, 2384949463751100, 11924747318755500, 59623736593777500
Offset: 0

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Author

Seiichi Manyama, Jul 04 2024

Keywords

Comments

Euler transform of 5 * A054662(n).

Examples

			A(x)^5 = 1 + 25*x + 375*x^2 + 4375*x^3 + 43750*x^4 + 393755*x^5 + ... .
		

Crossrefs

Programs

  • PARI
    b(n, k) = sumdiv(n, d, (gcd(d, k)==1)*(moebius(d)*k^(n/d)))/(k*n);
    my(N=30, x='x+O('x^N)); Vec(1/prod(k=1, N, (1 - x^k)^b(k, 5))^5)

Formula

G.f.: A(x) = 1 / ( Product_{k>=1} (1 - x^k)^A054662(k) )^5.

A372957 G.f. A(x) satisfies A(x)^2 = A(x^2) / (1 - 2*x)^2 with A(0)=1.

Original entry on oeis.org

1, 2, 5, 10, 22, 44, 91, 182, 370, 740, 1490, 2980, 5979, 11958, 23950, 47900, 95865, 191730, 383580, 767160, 1534549, 3069098, 6138628, 12277256, 24555341, 49110682, 98222947, 196445894, 392894839, 785789678, 1571585230, 3143170460, 6286352290, 12572704580, 25145431172
Offset: 0

Views

Author

Seiichi Manyama, Jul 04 2024

Keywords

Comments

Euler transform of 2 * A000048(n).

Examples

			A(x)^2 = 1 + 4*x + 14*x^2 + 40*x^3 + 109*x^4 + 276*x^5 + 678*x^6 + ... .
		

Crossrefs

Programs

  • PARI
    b(n, k) = sumdiv(n, d, (gcd(d, k)==1)*(moebius(d)*k^(n/d)))/(k*n);
    my(N=40, x='x+O('x^N)); Vec(1/prod(k=1, N, (1 - x^k)^b(k, 2))^2)

Formula

G.f.: A(x) = 1 / ( Product_{k>=1} (1 - x^k)^A000048(k) )^2.
Showing 1-2 of 2 results.