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a(0) = 0; a(n) is obtained by incrementing each digit of a(n-1) by 8.
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%I #22 Jun 26 2016 00:10:09

%S 0,8,16,914,17912,91517910,179139151798,91517911179139151716,

%T 1791391517999151791117913915914,

%U 91517911179139151717179139151799915179111791317912

%N a(0) = 0; a(n) is obtained by incrementing each digit of a(n-1) by 8.

%C In A061511-A061522, A061746-A061750 when the incremented digit exceeds 9 it is written as a 2-digit string. So 9+1 becomes the 2-digit string 10, etc.

%C Considering each term as a sequence of digits, the subsequences a(2n) and a(2n-1) converge to two different fixed points of the operation, 17913915179... and 915179111791391517.... More precisely, the digits of a(n) except the last are the first digits of a(n+2). - _M. F. Hasler_, Jun 24 2016

%C a(16) has 1270 decimal digits. - _Michael De Vlieger_, Jun 24 2016

%H Michael De Vlieger, <a href="/A061747/b061747.txt">Table of n, a(n) for n = 0..15</a>

%t NestList[FromDigits@ Flatten@ Map[IntegerDigits, IntegerDigits[#] + 8] &, 0, 9] (* _Michael De Vlieger_, Jun 24 2016, after _Harvey P. Dale_ at A061512 *)

%o (PARI) A061747(n=2, a=if(n,8), m=8)={for(n=2, n, a=eval(concat(apply(t->Str(t+m), digits(a))))); a} \\ If only the 2nd argument is given, then the operation is applied once to that argument. - _M. F. Hasler_, Jun 24 2016

%Y Cf. A061746 - A061750, A061511 - A061522; A061581 - A061587.

%K base,nonn

%O 0,2

%A _Amarnath Murthy_, May 08 2001

%E More terms from Larry Reeves (larryr(AT)acm.org), May 11 2001