A030686 Smallest nontrivial extension of n^2 which is a square.

16, 49, 900, 169, 256, 361, 4900, 6400, 8100, 10000, 12100, 1444, 16900, 19600, 22500, 25600, 28900, 3249, 36100, 40000, 44100, 48400, 52900, 57600, 62500, 67600, 72900, 78400, 84100, 90000, 96100, 102400, 108900, 115600, 122500

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• base

Comments

Nontrivial extension means appending at least one digit even if the number is already a square.

Links

• M. F. Hasler, Truncated squares, OEIS wiki, Jan 16 2012
• Index to sequences related to truncating digits of squares.

Crossrefs

Cf. A030687, A023110, A031149, A031150, A202303.

See also A023110 = A031149^2 and A202303 = A031150^2 for a related concept, and cross-references there (and in links) for the analog in bases other than 10. - M. F. Hasler, Sep 28 2014

Formula

a(n) = A030687(n)^2. - M. F. Hasler, Sep 28 2014

a(n) = A030666(n^2). - Alonso del Arte, Apr 01 2020