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.

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A112570 G.f. A(x) satisfies: A(x)^2 equals the g.f. of A110630, which consists entirely of numbers 1 through 4.

Original entry on oeis.org

1, 1, 1, 1, -1, 2, 0, 1, -2, 5, -5, 4, -6, 18, -30, 35, -43, 84, -167, 261, -352, 545, -1010, 1790, -2783, 4207, -7025, 12464, -21071, 33567, -54154, 92317, -159366, 266150, -435285, 725260, -1239404, 2112351, -3535532, 5894852, -9964767, 17008752, -28880694, 48645873
Offset: 0

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Author

Paul D. Hanna, Sep 14 2005

Keywords

Comments

A110630 is formed from every 2nd term of A083954, which also consists entirely of numbers 1 through 4.

Examples

			A(x) = 1 + x + x^2 + x^3 - x^4 + 2*x^5 + x^7 - 2*x^8 + 5*x^9 +...
A(x)^2 = 1 + 2*x + 3*x^2 + 4*x^3 + x^4 + 4*x^5 + 3*x^6 +...
A(x)^4 = 1 + 4*x + 10*x^2 + 20*x^3 + 27*x^4 + 36*x^5 +...
A(x)^4 (mod 8) = 1 + 4*x + 2*x^2 + 4*x^3 + 3*x^4 + 4*x^5 +...
G(x) = 1 + 4*x + 2*x^2 + 4*x^3 + 3*x^4 + 4*x^5 + 4*x^6 +...
where G(x) is the g.f. of A083954.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(d=2,m=4,A=1+m*x); for(j=2,d*n, for(k=1,m,t=polcoeff((A+k*x^j+x*O(x^j))^(1/m),j); if(denominator(t)==1,A=A+k*x^j;break))); polcoeff(Ser(vector(n+1,i,polcoeff(A,d*(i-1))))^(1/2),n)}

Formula

G.f. A(x) satisfies: A(x)^4 (mod 8) = g.f. of A083954.

A110629 Every 4th term of A083954 such that the self-convolution 4th power is congruent modulo 8 to A083954, which consists entirely of numbers 1 through 4.

Original entry on oeis.org

1, 3, 1, 3, 3, 2, 4, 3, 2, 3, 3, 4, 2, 2, 2, 1, 1, 4, 1, 3, 4, 3, 2, 2, 1, 1, 3, 4, 1, 1, 2, 3, 2, 2, 3, 4, 4, 1, 4, 4, 1, 4, 2, 3, 1, 2, 1, 4, 3, 3, 1, 4, 3, 3, 2, 3, 4, 2, 3, 4, 1, 2, 1, 3, 4, 3, 4, 1, 4, 2, 2, 3, 1, 4, 3, 2, 1, 4, 3, 4, 4, 2, 1, 4, 1, 4, 4, 2, 4, 4, 1, 3, 3, 4, 1, 1, 1, 4, 3, 2, 1, 3, 1, 2, 2
Offset: 0

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Author

Keywords

Examples

			A(x) = 1 + 3*x + x^2 + 3*x^3 + 3*x^4 + 2*x^5 + 4*x^6 + ...
A(x)^4 = 1 + 12*x + 58*x^2 + 156*x^3 + 315*x^4 + 620*x^5 +...
A(x)^4 (mod 8) = 1 + 4*x + 2*x^2 + 4*x^3 + 3*x^4 + 4*x^5 +...
G083954(x) = 1 + 4*x + 2*x^2 + 4*x^3 + 3*x^4 + 4*x^5 +...
where G083954(x) is the g.f. of A083954.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(d=4,m=4,A=1+m*x); for(j=2,d*n, for(k=1,m,t=polcoeff((A+k*x^j+x*O(x^j))^(1/m),j); if(denominator(t)==1,A=A+k*x^j;break)));polcoeff(A,d*n)}

Formula

a(n) = A083954(4*n) for n>=0.
Showing 1-2 of 2 results.