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Numbers n such that sigma(n) = sigma(n-1) + sigma(n-2).
17

%I #27 Dec 15 2017 17:35:45

%S 3,4,24,1968,3264,5016,60456,1016508,4420164,12055512,14365608,

%T 25726728,27896424,66562308,72764736,98734968,175186656,224868312,

%U 253694928,288657204,386668344,421575408,504737748,630645456,1493548000,1653797796,2120325012,2221315152

%N Numbers n such that sigma(n) = sigma(n-1) + sigma(n-2).

%C No other terms less than 1000000000. - Sam Handler (sam_5_5_5_0(AT)yahoo.com), Nov 23 2004

%H Donovan Johnson and Giovanni Resta, <a href="/A065900/b065900.txt">Table of n, a(n) for n = 1..112</a> (terms < 10^13, first 50 terms from Donovan Johnson)

%F a(n) = A076530(n) + 1 = A104149(n) + 2. - _Alex Ratushnyak_, Jul 06 2013

%o (PARI) s1=1; s2=3; for(n=3, 10^8, s3=sigma(n); if(s3==s1+s2, print1(n ", ")); s1=s2; s2=s3) /* _Donovan Johnson_, Apr 06 2013 */

%Y Cf. A000203, A076530, A104149.

%K nonn

%O 1,1

%A _Jason Earls_, Dec 07 2001

%E More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Nov 23 2004