4 lines
247 B
Text
4 lines
247 B
Text
ssd(n)=n=digits(n); sum(i=1, #n, n[i]^2);
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happy(n)=while(n>6, n=ssd(n)); n==1;
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ct(n)=my(f=n!,s=10^n-1,d); forvec(v=vector(9,i,[0,n]), d=vector(9,i, if(i>8,n,v[i+1])-v[i]); if(happy(sum(i=1,9,d[i]*i^2)), s-=f/prod(i=1,9,d[i]!)/v[1]!), 1); s;
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ct(8)
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