A055435 (1/18)*Difference between concatenation of n and n^2 and concatenation of n^2 and n.

0, -1, -3, 14, 15, 15, 14, 12, 9, 5, -55, -126, -208, -301, -405, -520, -646, -783, -931, -1090, -1260, -1441, -1633, -1836, -2050, -2275, -2511, -2758, -3016, -3285, -3565, 12144, 12342, 12529, 12705, 12870, 13024, 13167, 13299, 13420

Offset: 1

Author

Henry Bottomley, May 18 2000

Keywords

• base
• easy
• sign

Programs

Mathematica

Table[((n*10^IntegerLength[x = n^2] + x) - (n^2*10^IntegerLength[n] + n))/18, {n, 40}] (* Jayanta Basu, Jul 12 2013 *)

Formula

a(n) = (A053061(n) - A055436(n))/18 = n*(10^floor(2*log_10(W2)+1) - 1 - n*(10^floor(log_10(W2)+1)-1))/18.