|
%I #6 Feb 21 2016 19:51:32
%S 0,1,11,2,12,112,3,13,113,23,4,14,33,24,124,5,15,115,25,125,44,6,16,
%T 116,26,45,145,36,7,17,55,27,127,255,37,137,8,18,47,28,128,247,38,57,
%U 157,9,19,119,29,67,167,39,139,457,239,49,77,68,168,277,59,159,377,259,78,178,69,169,1169
%N Smallest m such that A267238(m) = n.
%t seq={0};f[n_]:=Total[IntegerDigits[n]*(IntegerDigits[n]+1)/2];lst=f/@Range[10^5];
%t Do[AppendTo[seq,First[Position[lst,m]]],{m,1,100}];seq//Flatten
%o (PARI) strd(n) = {my(d = digits(n)); sum(k=1, #d, d[k]*(d[k]+1)/2);}
%o a(n) = {m = 0; while(strd(m) != n, m++); m;} \\ _Michel Marcus_, Jan 13 2016
%Y Cf. A267238.
%K base,easy,nonn
%O 0,3
%A _Ivan N. Ianakiev_, Jan 13 2016
|
