cp's OEIS Frontend

A102718 a(n) = a(n-1) + (sum of the last two digits of the sequence so far); a(0)=0; a(1)=1.

%I A102718 #16 May 19 2018 09:12:11
%S A102718 0,1,2,5,12,15,21,24,30,33,39,51,57,69,84,96,111,113,117,125,132,137,
%T A102718 147,158,171,179,195,209,218,227,236,245,254,263,272,281,290,299,317,
%U A102718 325,332,337,347,358,371,379,395,409,418,427,436,445,454,463,472,481,490,499,517,525,532,537,547,558,571
%N A102718 a(n) = a(n-1) + (sum of the last two digits of the sequence so far); a(0)=0; a(1)=1.
%H A102718 Harvey P. Dale, <a href="/A102718/b102718.txt">Table of n, a(n) for n = 0..1000</a>
%F A102718 a(n + 20) = 200 + a(n) for n > 17. - _David A. Corneth_, May 11 2018
%e A102718 96 + (9 + 6) = 111;
%e A102718 111 + (1 + 1) = 113;
%e A102718 113 + (1 + 3) = 117.
%t A102718 Join[{0,1,2,5},NestList[#+Total[Take[IntegerDigits[#],-2]]&,12,60]] (* _Harvey P. Dale_, May 11 2018 *)
%o A102718 (PARI) first(n) = {n = max(n, 5); res = [0, 1, 2, 5, 12]; res = concat(res, vector(n - 5)); for(i = 6, min(n, 37), res[i] = res[i-1] + vecsum(digits(res[i-1] % 100)));
%o A102718 for(i = 38, n, res[i] = res[i - 20] + 200); res} \\ _David A. Corneth_, May 11 2018
%Y A102718 Cf. A102039.
%K A102718 base,easy,nonn
%O A102718 0,3
%A A102718 _Eric Angelini_, Feb 06 2005
%E A102718 Corrected and extended by _Harvey P. Dale_, May 11 2018