A018233 Consider pairs (k,m) such that k^2 begins with a 1 and when the 1 is changed to a 2 we again get a square, m^2; sequence gives values of k for primitive solutions.

105, 3375, 14025, 326625, 10846875, 43708125, 1015903125, 34856484375, 136203890625, 111998513671875, 424408358203125, 359825755224609375, 1322343959384765625, 1155912765076904296875, 4119741961077392578125, 3712890686865325927734375

Offset

1,1

Comments

Primitive here means that if (k,m) is a solution, solutions like (10^t*k,10^t*m) are ignored. - Sean A. Irvine, Feb 05 2019

References

Posting by Noam D. Elkies to netnews circa Oct 15 1992.

Links

Sean A. Irvine, Table of n, a(n) for n = 1..40

Noam D. Elkies, Cliff Puzzle 8: Squares and Squares and Squares, rec.puzzles Archive (pickover), part 29 of 35, 17 Aug 1993.

Crossrefs

Cf. A018232.

Sequence in context: A166821 A166803 A262075 * A154633 A122814 A289952

Adjacent sequences: A018230 A018231 A018232 * A018234 A018235 A018236

Keyword

nonn,base

Author

N. J. A. Sloane

Extensions

Missing terms inserted and more terms from Sean A. Irvine, Feb 05 2019

Status

approved