OFFSET
1,2
COMMENTS
A178028 is a subsequence of this sequence.
When n divides q, n divides d(D)*(10^D - 1) because q = 10*n^2 - d(D)*(10^D - 1). If n is prime, n divides (10^D - 1); for example, the prime term 271 divides 10^5 - 1 = 99999 = 271*369.
LINKS
Eric Weisstein's World of Mathematics, Repunits
EXAMPLE
429 is in the sequence because 429^2 = 184041 and 840411/429 = 1959.
MAPLE
for n from 1 to 10^6 do: d:=convert(n^2, base, 10):n1:=nops(d):s:=sum('d[i]*10^i', 'i'=1..n1-1)+d[n1]:if irem(s, n)=0 then printf(`%d, `, n):else fi:od:
MATHEMATICA
Select[Range[100000], Mod[FromDigits[RotateLeft[IntegerDigits[#^2]]], #] == 0 &] (* T. D. Noe, Jul 27 2012 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Lagneau, May 15 2010
STATUS
approved