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A262713 Numbers k such that the sum of digits of k^2 is 10. 2
8, 19, 35, 46, 55, 71, 80, 145, 152, 179, 190, 251, 332, 350, 361, 449, 451, 460, 548, 550, 649, 710, 800, 1450, 1520, 1790, 1900, 2510, 3320, 3500, 3610, 4490, 4499, 4510, 4600, 5480, 5500, 6490, 7100, 8000, 14500, 15200, 17900, 19000, 20249, 20251, 24499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

From Altug Alkan, Sep 29 2015: (Start)

Subsequence of A001651.

If a(n)+1 mod 9 != 0 then a(n)-1 mod 9 = 0;

if a(n)-1 mod 9 != 0 then a(n)+1 mod 9 = 0;

a(n)^2 - 1 mod 9 = 0. (End)

A135027(n)*10^k is a term for all n > 0, k >= 0. - Michael S. Branicky, Aug 19 2021

LINKS

Michael S. Branicky, Table of n, a(n) for n = 1..244

Michael S. Branicky, Python program

EXAMPLE

19 is in sequence because 19^2 = 361 and 3+6+1 = 10.

MATHEMATICA

Select[Range[10^5], Total[IntegerDigits[#^2]] == 10 &]

PROG

(MAGMA) [n: n in [1..3*10^4] | &+Intseq(n^2) eq 10 ];

(PARI) for(n=1, 1e6, if (sumdigits(n^2) == 10, print1(n", "))) \\ Altug Alkan, Sep 28 2015

(Python) # See linked program to go to larger numbers

def ok(n): return sum(map(int, str(n*n))) == 10

print(list(filter(ok, range(25000)))) # Michael S. Branicky, Aug 19 2021

CROSSREFS

Cf. similar sequences listed in A262711.

Cf. A004159, A061910, A135027.

Sequence in context: A146222 A140672 A230098 * A135027 A158916 A045557

Adjacent sequences:  A262710 A262711 A262712 * A262714 A262715 A262716

KEYWORD

nonn,base

AUTHOR

Vincenzo Librandi, Sep 28 2015

STATUS

approved

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Last modified May 26 13:59 EDT 2022. Contains 354092 sequences. (Running on oeis4.)