A262711 Numbers k such that sum of digits of k^2 is 7.

4, 5, 32, 40, 49, 50, 149, 320, 400, 490, 500, 1049, 1490, 3200, 4000, 4900, 5000, 10490, 14900, 32000, 40000, 49000, 50000, 104900, 149000, 320000, 400000, 490000, 500000, 1049000, 1490000, 3200000, 4000000, 4900000, 5000000, 10490000, 14900000

Offset: 1

Author

Vincenzo Librandi, Sep 28 2015

Keywords

• nonn
• base

Comments

Subsequence of A156638. [Bruno Berselli, Sep 28 2015]

Examples

			4 is in sequence because 4^2 = 16 and 1+6 = 7.
		

Crossrefs

Cf. sum of digits of n^2 is k: A052216 (k=4), this sequence (k=7), A262712 (k=9), A262713 (k=10).

Cf. A004159, A061910, A156638.

Cf. A215614.

Programs

Magma

[n: n in [1..2*10^7] | &+Intseq(n^2) eq 7];

Mathematica

Select[Range[10^7], Total[IntegerDigits[#^2]] == 7 &]

PARI

for(n=1, 1e8, if (sumdigits(n^2) == 7, print1(n", "))) \\ Altug Alkan, Sep 28 2015