cp's OEIS Frontend

A361741 Starting positions of digit triples in the decimal expansion of Pi where the sum of the first 2 equals the third.

%I A361741 #66 May 02 2023 13:56:13
%S A361741 1,3,10,29,61,73,83,106,117,132,177,192,195,198,241,248,251,281,309,
%T A361741 311,333,362,381,393,432,477,486,494,504,508,525,532,536,555,602,611,
%U A361741 628,647,662,674,689,699,710,747,755,760,771,806,853,856,887,899,927,934,966,969,989
%N A361741 Starting positions of digit triples in the decimal expansion of Pi where the sum of the first 2 equals the third.
%C A361741 The first digit of Pi, "3", is reckoned as position 1.
%C A361741 This pattern happens from the first digit of Pi, so it seems to be pretty basic.
%H A361741 <a href="/index/Ph#Pi314">Index entries for sequences related to the number Pi</a>
%F A361741 Integers k such that A000796(k) + A000796(k+1) = A000796(k+2).
%F A361741 Equivalently, A110883(k) = A000796(k+2).
%F A361741 In a random model of this sequence (call it A(n)), A(n) ~ kn with probability 1, where k = 200/11. - _Charles R Greathouse IV_, Mar 28 2023
%e A361741 1 is the first term, since the first two digits 3 and 1 add up to 4.
%e A361741 3 is the second term, since 4 + 1 = 5.
%e A361741 10 is next, since 3 + 5 = 8.
%o A361741 (MATLAB)
%o A361741 p=char(vpa(pi,1000));p(2)='3';
%o A361741 for i=2:strlength(p)-2
%o A361741   if str2num(p(i))+str2num(p(i+1))==str2num(p(i+2)) fprintf('%i,',i-1)  end
%o A361741 end
%Y A361741 Cf. A000796, A110883.
%K A361741 nonn,base
%O A361741 1,2
%A A361741 _Aaron T Cowan_, Mar 22 2023