A225301 Number of solutions to rev(x^2) = rev(x)^2 with at most n digits, where the function rev(x) reverses the digits of x.

4, 10, 25, 64, 154, 363, 820, 1811, 3873, 8161, 16682, 33757, 66865, 130938, 251983, 480794, 903982, 1685564, 3106009, 5677864, 10276936, 18464659, 32891188, 58169965, 102136773, 178096365, 308593320, 531191385, 909227947, 1546356486, 2617639293

Offset

1,1

Comments

Numbers (other than 0) that end in zero are excluded.

Links

Table of n, a(n) for n=1..31.

David Radcliffe, Python code for calculating a(n).

Formula

Equals one more than the partial sums of A098701.

Example

For n = 2 the a(2) = 10 solutions are 0, 1, 2, 3, 11, 12, 13, 21, 22, 31.

Crossrefs

Cf. A085305, A061909.

Sequence in context: A021004 A020709 A020734 * A298412 A289245 A347725

Adjacent sequences: A225298 A225299 A225300 * A225302 A225303 A225304

Keyword

nonn,base

Author

David Radcliffe, May 05 2013

Status

approved