A110643 Every 2nd term of A083950 where the self-convolution 2nd power is congruent modulo 4 to A083950, which consists entirely of numbers 1 through 10.
1, 5, 10, 5, 10, 3, 5, 10, 10, 10, 5, 5, 5, 5, 5, 8, 10, 10, 5, 10, 7, 10, 5, 10, 5, 7, 5, 5, 10, 10, 7, 10, 10, 5, 5, 9, 5, 5, 5, 10, 8, 10, 10, 10, 10, 8, 5, 5, 10, 10, 5, 10, 10, 10, 5, 6, 5, 5, 10, 5, 10, 10, 5, 10, 10, 1, 5, 5, 10, 10, 5, 5, 5, 10, 5, 5, 10, 5, 5, 10, 4, 10, 10, 5, 5, 6, 10
Offset: 0
Keywords
Examples
A(x) = 1 + 5*x + 10*x^2 + 5*x^3 + 10*x^4 + 3*x^5 + 5*x^6 +... A(x)^2 = 1 + 10*x + 45*x^2 + 110*x^3 + 170*x^4 + 206*x^5 +... A(x)^2 (mod 4) = 1 + 2*x + x^2 + 2*x^3 + 2*x^4 + 2*x^5 +... G(x) = 1 + 10*x + 5*x^2 + 10*x^3 + 10*x^4 + 2*x^5 + 5*x^6 +... where G(x) is the g.f. of A083950.
Programs
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PARI
{a(n)=local(d=2,m=10,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)}