# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a100543 Showing 1-1 of 1 %I A100543 #23 Dec 25 2022 19:58:22 %S A100543 0,3,3,0,10,12,1,24,25,32,116,12,412,109,126,2389,12497,28772,126, %T A100543 72795,247786,770213,159378001963452599312,2169128,-26,311,378,789, %U A100543 10015050,75,74253544,7881195,2461717833658872781238383813854943728,51,17,-250,855,2,-29979,3087,215308,123456790123456790123456790123456790123452,132813776,1086162642,1836311902,400276874544 %N A100543 Sum of first n terms of A_n (signed values). %C A100543 Since the sequences in the OEIS occasionally change their initial terms (for editorial reasons), this is an especially ill-defined sequence! - _N. J. A. Sloane_, Jan 01 2005 %C A100543 The next term, a(47), is currently unknown. - _Jianing Song_, Oct 07 2018 %H A100543 Index entries for sequences whose definition involves A_n (or An). %e A100543 A000001 (Number of groups of order n) begins 0,... -> a(1) = 0 %e A100543 A000002 (Kolakoski sequence) begins 1, 2,... -> a(2) = 3 %e A100543 A000003 begins 1, 1, 1,... -> a(3) = 3 %e A100543 A000004 (The zero sequence) begins 0, 0, 0, 0,... -> a(4) = 0 %e A100543 A000005 (The number of divisors) begins 1, 2, 2, 3, 2, ... -> a(5) = 10 %e A100543 ... %e A100543 A000010 (Euler totient function) begins 1, 1, 2, 2, 4, 2, 6, 4, 6, ... so a(10) = 1 + 1 + 2 + 2 + 4 + 2 + 6 + 4 + 6 + 4 = 32. %Y A100543 Cf. A031135, A031214, A039928. %K A100543 dumb,easy,sign %O A100543 1,2 %A A100543 _Russ Cox_ %E A100543 Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 27 2004 %E A100543 a(1) changed from 1 to 0 by _Jianing Song_, Jul 02 2018 %E A100543 Extend by _Jianing Song_, Oct 07 2018 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE