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A249971 Numbers whose squares remain squares when prepended with 5 and appended with 25 in base 10. 5
16, 30730, 3727084, 3127636818781854350, 7536101752216453484, 52452254824270668843034, 260517421591511559294554416, 20815875053039440273965644350185324640 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
30730^2 = 944332900, 594433290025 = 770995^2.
PROG
(PARI) isok(n) = issquare(eval(concat(5, concat(Str(n^2), 25)))); \\ Michel Marcus, Nov 20 2014
CROSSREFS
Sequence in context: A017416 A265618 A087518 * A221244 A280656 A265662
KEYWORD
nonn,base
AUTHOR
Chai Wah Wu, Nov 19 2014
STATUS
approved

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Last modified June 21 14:37 EDT 2024. Contains 373547 sequences. (Running on oeis4.)