Search: id:A129588 Results 1-1 of 1 results found. %I A129588 %S A129588 16,64,96,128,208,192,224,384,288,320,512,384,496,640,480,512,768,768, %T A129588 608,896,672,704,1248,768,912,1152,864,1152,1280,960,992,1664,1344,1088, %U A129588 1536,1152,1184,1984,1536,1280,1936,1344,1728,1920,1440 %N A129588 Expansion of q^-1 *theta_2(q)^4 in powers of q^2. %D A129588 K. Bobek, Einleitung in die Theorie der elliptischen Funktionen, Teubner Leipzig, 1884, p. 101. %F A129588 G.f. sum{n>=0, a(n)*x^(2n+1) } = theta2(q)^4 = theta3(q)^4 - theta4(q)^4. %F A129588 Expansion of 16*psi(q)^4 in powers of q where psi() is a Ramanujan theta function. - Michael Somos Jun 11 2007 %F A129588 Number of solutions of 2n+1 = (x^2+y^2+z^2+w^2)/4 in odd integers. - Michael Somos Jun 11 2007 %F A129588 G.f.: 16 * (Product_{k>0} (1-x^k)(1+x^k)^2)^4. - Michael Somos Jun 11 2007 %o A129588 (PARI) {a(n)= if(n<0, 0, 16*sigma(2*n+1))} /* Michael Somos Jun 11 2007 */ %Y A129588 a(n) = 16*A008438(n) = A000118(n)-A096727(n). Cf. A000122, A002448. %Y A129588 Sequence in context: A062320 A117453 A039370 this_sequence A043193 A043973 A153262 %Y A129588 Adjacent sequences: A129585 A129586 A129587 this_sequence A129589 A129590 A129591 %K A129588 nonn %O A129588 0,1 %A A129588 Ralf Stephan (ralf(AT)ark.in-berlin.de), May 30 2007 Search completed in 0.001 seconds