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 A119298 #29 Dec 10 2024 11:26:09
%S A119298 2,34,551,6338,72319,809360,9543704,104376285,1136782466,12273965395,
%T A119298 134080968533,1448607569210
%N A119298 Total number of 7's digits in the first 10^n primes.
%e A119298 At a(1)=2 there are 2 7's digits in the first 10^1 primes.
%p A119298 A119298 := proc(n) option remember: local k,s,lim: if(n=0)then return 0:fi: lim:=10^n: s:=procname(n-1): for k from 10^(n-1)+1 to lim do s:=s+nops([SearchAll("7",convert(ithprime(k),string))]): od: return s: end: seq(A119298(n),n=1..4); # _Nathaniel Johnston_, May 09 2011
%t A119298 Table[Count[IntegerDigits[Prime[Range[10^n]]], 7, 2], {n, 6}] (* _Robert Price_, May 02 2019 *)
%t A119298 Table[Total[Table[DigitCount[p,10,7],{p,Prime[Range[10^n]]}]],{n,7}] (* The program generates the first seven terms of the sequence. *) (* _Harvey P. Dale_, Dec 10 2024 *)
%Y A119298 Cf. A119290, A119291, A119292, A119293, A119294, A119295, A119296, A119297, A119299, A119300.
%K A119298 more,nonn,base
%O A119298 1,1
%A A119298 _Enoch Haga_, May 13 2006
%E A119298 Offset changed from 0 to 1 by _Nathaniel Johnston_, May 09 2011
%E A119298 a(8)-a(11) from _Robert Price_, Nov 05 2013
%E A119298 a(12) from _Marek Hubal_, Mar 04 2019