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A290227
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Numbers n such that A290223(n) = 11.
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0
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8, 17, 26, 29, 35, 38, 47, 56, 65, 74, 83, 92, 149, 158, 167, 197
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refs;
listen;
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internal format)
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OFFSET
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1,1
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COMMENTS
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This sequence is believed to be finite. If it exists, a(17) > 10^5.
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LINKS
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EXAMPLE
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26 is in this sequence because 26 - (2+6)^2 = -38. Then -38 + (3+8)^2 = 83. Then 83 - (8+3)^2 = -38, and so on.
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PROG
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(PARI)
a(n)=k=n; c=1; v=List(); listput(v, k); while(c, if(k>=0, k-=sumdigits(k)^2; c+=1; if(k==2||k==3||k==0||k==6||k==9, return(k)); if(vecsearch(Vec(v), k), return(sumdigits(abs(k)))); listput(v, k)); if(k<0, k+=sumdigits(-k)^2; c+=1; if(k==2||k==3||k==0||k==6||k==9, return(k)); if(vecsearch(Vec(v), k), return(sumdigits(abs(k)))); listput(v, k)); c+=1)
for(n=1, 10^5, if(a(n)==11, print1(n, ", ")))
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CROSSREFS
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KEYWORD
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nonn,base,fini,full
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AUTHOR
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STATUS
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approved
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