Search: id:A074784 Results 1-1 of 1 results found. %I A074784 %S A074784 1,5,14,30,55,91,140,204,285,286,290,299,315,340,376,425,489,570,670, %T A074784 674,683,699,724,760,809,873,954,1054,1175,1184,1200,1225,1261,1310, %U A074784 1374,1455,1555,1676,1820,1836,1861,1897,1946,2010,2091,2191,2312,2456 %N A074784 a(n) = a(n-1) + square of the sum of digits of n. %D A074784 R. E. Kennedy and C. N. Cooper, An extension of a theorem by Cheo and Yien concerning digital sums. Fibonacci Q. 29, No. 2, 145-149 (1991). %D A074784 H. Riede, Asymptotic estimation of a sum of digits. Fibonacci Q. 36, No. 1, 72-75 (1998). %F A074784 a(n)= Sum_{k=1..n} s(k)^2 = Sum_{k=1..n} A007953(k)^2, where s(k) denote the sum of the digits of k in decimal representation. Asymptotic expression: a(n-1) = Sum_{k=1..n-1} s(k)^2 = 20.25*n*log10(n)^2 + O(n*log10(n)) . In general: Sum_{k=1..n-1} s(k)^m = n*((9/2)*log10(n))^m + O(n*log10(n)^(m-1)). %Y A074784 Cf. A037123. %Y A074784 Sequence in context: A053461 A136135 A096893 this_sequence A109678 A000330 A166068 %Y A074784 Adjacent sequences: A074781 A074782 A074783 this_sequence A074785 A074786 A074787 %K A074784 nonn,base %O A074784 1,2 %A A074784 Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Sep 07 2002 Search completed in 0.001 seconds