Search: id:A013959 Results 1-1 of 1 results found. %I A013959 %S A013959 1,2049,177148,4196353,48828126,362976252,1977326744,8594130945, %T A013959 31381236757,100048830174,285311670612,743375541244,1792160394038, %U A013959 4051542498456,8649804864648,17600780175361,34271896307634 %N A013959 sigma_11(n), the sum of the 11-th powers of the divisors of n. %C A013959 If the canonical factorization of n into prime powers is the product of p^e(p) then sigma_k(n) = Product_p ((p^((e(p)+1)*k))-1)/(p^k-1). %C A013959 Sum_{d|n} 1/d^k is equal to sigma_k(n)/n^k. So sequences A017665-A017712 also give the numerators and denominators of sigma_k(n)/n^k for k = 1..24. The power sums sigma_k(n) are in sequences A000203 (k=1), A001157-A001160 (k=2,3,4,5), A013954-A013972 for k = 6,7,...,24. - comment from Ahmed Fares (ahmedfares(AT)my-deja.com), Apr 05 2001. %C A013959 Related to congruence properties of the Ramanujan tau function T since T(n)==a(n) (mod 691) - Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 28 2002 %H A013959 T. D. Noe, Table of n, a(n) for n=1..1000 %F A013959 G.f. sum(k>=1, k^11*x^k/(1-x^k)). - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 21 2003 %t A013959 lst={};Do[AppendTo[lst,DivisorSigma[11,n]],{n,5!}];lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Mar 11 2009] %o A013959 (Other) sage: [sigma(n,11)for n in xrange(1,18)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 04 2009] %Y A013959 Sequence in context: A071116 A060949 A017685 this_sequence A036089 A123095 A045059 %Y A013959 Adjacent sequences: A013956 A013957 A013958 this_sequence A013960 A013961 A013962 %K A013959 nonn,mult %O A013959 1,2 %A A013959 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.001 seconds