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 1-3 of 3 results.

A106225 Self-convolution 6th power equals A106224, which consists entirely of digits {0,1,2,3,4,5} after the initial terms {1,6}.

Original entry on oeis.org

1, 1, -2, 7, -27, 114, -506, 2322, -10919, 52316, -254369, 1251563, -6218656, 31153743, -157167147, 797682007, -4069817562, 20860266354, -107358128720, 554533772363, -2873667741743, 14935575580894, -77833224795929, 406595414780038, -2128748177726089, 11167899337858904
Offset: 0

Views

Author

Paul D. Hanna, May 01 2005

Keywords

Examples

			A(x) = 1 + x - 2*x^2 + 7*x^3 - 27*x^4 + 114*x^5 - 506*x^6 +-...
A(x)^6 = 1 + 6*x + 3*x^2 + 2*x^3 + 3*x^4 + 3*x^8 + 4*x^9 +...
A106224 = {1,6,3,2,3,0,0,0,3,4,3,0,0,0,3,2,0,0,0,0,3,2,...}.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+6*x);if(n==0,1, for(j=1,n, for(k=0,5,t=polcoeff((A+k*x^j+x*O(x^j))^(1/6),j); if(denominator(t)==1,A=A+k*x^j;break))); return(polcoeff((A+x*O(x^n))^(1/6),n)))}

Formula

Limit a(n+1)/a(n) = -5.502856676359094846755190514140489974645...

A106226 Coefficients of g.f. A(x) where 0 <= a(n) <= 6 for all n>1, with initial terms {1,7}, such that A(x)^(1/7) consists entirely of integer coefficients.

Original entry on oeis.org

1, 7, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Paul D. Hanna, May 01 2005

Keywords

Comments

Equals the self-convolution 7th power of A106227. What is the frequency of occurrence of the nonzero digits?

Examples

			A(x) = 1 + 7*x + x^7 + 4*x^14 + 6*x^21 + 5*x^28 + x^35 + 6*x^42 +...
A(x)^(1/7) = 1 + x - 3*x^2 + 13*x^3 - 65*x^4 + 351*x^5 - 1989*x^6 +-...
A106227 = {1,1,-3,13,-65,351,-1989,11650,-69900,427167,...}.
		

Crossrefs

Programs

  • PARI
    {a(n)=local(A=1+7*x);if(n==0,1, for(j=1,n, for(k=0,6,t=polcoeff((A+k*x^j+x*O(x^j))^(1/7),j); if(denominator(t)==1,A=A+k*x^j;break))); return(polcoeff(A+x*O(x^n),n)))}

A352705 G.f. A(x) satisfies: A(x)^7 = A(x^7) + 7*x.

Original entry on oeis.org

1, 1, -3, 13, -65, 351, -1989, 11650, -69900, 427167, -2648438, 16612947, -105215448, 671760933, -4318468134, 27926126553, -181520036178, 1185220461867, -7769787812787, 51117085998498, -337373170647840, 2233091755252871, -14819626692452231, 98582852467595847
Offset: 0

Views

Author

Paul D. Hanna, Mar 29 2022

Keywords

Comments

Not the same as A106227.

Examples

			G.f.: A(x) = 1 + x - 3*x^2 + 13*x^3 - 65*x^4 + 351*x^5 - 1989*x^6 + 11650*x^7 - 69900*x^8 + 427167*x^9 - 2648438*x^10 + ...
such that A(x)^7 = A(x^7) + 7*x, as illustrated by:
A(x)^7 = 1 + 7*x + x^7 - 3*x^14 + 13*x^21 - 65*x^28 + 351*x^35 - 1989*x^42 + 11650*x^49 - 69900*x^56 + 427167*x^63 - 2648438*x^70 + ...
		

Crossrefs

Programs

  • PARI
    {a(n) = my(A=1+x); for(i=1,n,
    A = (subst(A,x,x^7) + 7*x + x*O(x^n))^(1/7));
    polcoeff(A,n)}
    for(n=0,30,print1(a(n),", "))
Showing 1-3 of 3 results.