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Numbers k such that A006577(k!) sets a new record.
2

%I #5 Aug 04 2021 07:44:16

%S 2,3,4,5,7,8,9,11,12,14,17,21,26,29,33,34,37,44,45,47,48,51,52,55,58,

%T 61,70,78,85,89,91,92,93,96,97,98,105,107,113,114,118,124,129,135,145,

%U 148,149,150,152,157,161,173,175,179,184,192,201,205,206,209,212,213

%N Numbers k such that A006577(k!) sets a new record.

%o (PARI) a6577(n0)={my(n=n0,k=0);while(n>1,k++;n=if(n%2,3*n+1,n/2));k};

%o a346782(limit)={my(msteps=0);for(k=0,limit,my(m=a6577(k!));if(m>msteps,print1(k,", ");msteps=m))};

%o a346782(215)

%Y The corresponding record numbers of steps are A346783.

%Y Cf. A006577, A070974, A346592, A346593.

%K nonn

%O 1,1

%A _Hugo Pfoertner_, Aug 04 2021