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.
%I A001553 M4149 N1723 #53 Oct 26 2024 10:15:02 %S A001553 6,21,91,441,2275,12201,67171,376761,2142595,12313161,71340451, %T A001553 415998681,2438235715,14350108521,84740914531,501790686201, %U A001553 2978035877635,17706908038281,105443761093411,628709267031321,3752628871164355,22418196307542441,134023513204581091 %N A001553 a(n) = 1^n + 2^n + ... + 6^n. %C A001553 For the o.g.f.s of such sequences see the W. Lang link under A196837. The e.g.f.s are trivial. - _Wolfdieter Lang_, Oct 14 2011 %C A001553 a(n) is divisible by 7 iff n is not divisible by 6 (see De Koninck & Mercier reference). Example: a(5)= 12201 = 7 * 1743 and a(6) = 67171 = 9595 * 7 + 6. - _Bernard Schott_, Mar 06 2020 %D A001553 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 813. %D A001553 J.-M. De Koninck and A. Mercier, 1001 Problèmes en Théorie Classique des Nombres, Problème 289 pp. 45, 194, Ellipses, Paris, (2004). %D A001553 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001553 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A001553 T. D. Noe, <a href="/A001553/b001553.txt">Table of n, a(n) for n = 0..200</a> %H A001553 M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy]. %H A001553 INRIA Algorithms Project, <a href="http://ecs.inria.fr/services/structure?nbr=366">Encyclopedia of Combinatorial Structures 366</a> %H A001553 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (21, -175, 735, -1624, 1764, -720). %F A001553 a(n) = Sum_{k=1..6} k^n. %F A001553 From _Wolfdieter Lang_, Oct 10 2011: (Start) %F A001553 E.g.f.: (1-exp(6*x))/(exp(-x)-1) = Sum_{j=1..6} exp(j*x) (trivial). %F A001553 O.g.f.: (2 - 7*x)*(3 - 42*x + 203*x^2 - 392*x^3 + 252*x^4)/Product_{j=1..6} (1 - j*x). %F A001553 From the Laplace transformation of the e.g.f. (with argument 1/p, and multiplied with 1/p), which yields the partial fraction decomposition of the given o.g.f., namely Sum_{j=1..6} 1/(1 - j*x). %F A001553 (End) %t A001553 Table[Total[Range[6]^n], {n, 0, 40}] (* _T. D. Noe_, Oct 10 2011 *) %Y A001553 Column 6 of array A103438, A001552. %K A001553 nonn,easy %O A001553 0,1 %A A001553 _N. J. A. Sloane_ %E A001553 More terms from _Jon E. Schoenfield_, Mar 24 2010