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A249972 Numbers whose squares remain squares when prepended with 6 and appended with 25 in base 10. 3
4719393690, 11807874630, 27742949118597124246940412263153220, 3115332518157379156757021966320555019484, 260714191448671809506865610677483779874998640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

4719393690^2 = 22272676801211816100, 62227267680121181610025 = 249453938995^2.

PROG

(PARI) isok(n) = issquare(eval(concat([6, Str(n^2), 25]))) \\ Michel Marcus, Jul 20 2017

CROSSREFS

Cf. A249621, A249968, A249969, A249970, A249971, A250433, A250434, A250435.

Sequence in context: A124977 A128172 A050259 * A233494 A175568 A224472

Adjacent sequences:  A249969 A249970 A249971 * A249973 A249974 A249975

KEYWORD

nonn,base,more

AUTHOR

Chai Wah Wu, Nov 22 2014

EXTENSIONS

a(5) from Chai Wah Wu, Jul 19 2017

STATUS

approved

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Last modified June 17 04:26 EDT 2019. Contains 324183 sequences. (Running on oeis4.)