A236748 -id:A236748 - cp's OEIS frontend

A236750 Positive integers k such that k^3 divided by the digital sum of k is a square.

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 24, 36, 48, 81, 100, 144, 150, 192, 196, 200, 225, 242, 288, 300, 320, 324, 375, 400, 441, 484, 500, 512, 600, 640, 648, 700, 704, 735, 800, 832, 882, 900, 960, 1014, 1088, 1200, 1250, 1452, 1458, 1521, 1815, 2023, 2025, 2028

Offset: 1

Colin Barker, Jan 30 2014

The sequence is infinite since if m = 10^(2*j) then m^3 / digitsum(m) = m^(6*k). - Marius A. Burtea, Dec 21 2018

			192 is in the sequence because the digital sum of 192 is 12, and 192^3/12 = 589824 = 768^2.

Colin Barker, Table of n, a(n) for n = 1..1000

Cf. A001102, A007953, A236748, A236749, A236751.

[n: n in [1..1500] | IsIntegral((n^3)/(&+Intseq(n))) and IsSquare((n^3)/(&+Intseq(n)))]; // Marius A. Burtea, Dec 21 2018

s=[]; for(n=1, 5000, d=sumdigits(n); if(n^3%d==0 && issquare(n^3\d), s=concat(s, n))); s

A236751 Positive integers n such that n^3 divided by the digital sum of n is a cube.

Original entry on oeis.org

1, 8, 10, 26, 44, 62, 80, 100, 116, 134, 152, 170, 206, 224, 242, 260, 314, 332, 350, 404, 422, 440, 512, 530, 602, 620, 710, 800, 999, 1000, 1016, 1034, 1052, 1070, 1106, 1124, 1142, 1160, 1214, 1232, 1250, 1304, 1322, 1340, 1412, 1430, 1502, 1520, 1610

Offset: 1

Colin Barker, Jan 30 2014

			152 is in the sequence because the digital sum of 152 is 8, and 152^3/8 = 438976 = 76^3.

Colin Barker, Table of n, a(n) for n = 1..1000

Cf. A007953, A236748, A236749, A236750.

s=[]; for(n=1, 3000, d=sumdigits(n); if(n^3%d==0 && ispower(n^3\d, 3), s=concat(s, n))); s

A236749 Positive integers n such that n^2 divided by the digital sum of n is a cube.

Original entry on oeis.org

1, 8, 81, 512, 1000, 2592, 6400, 8000, 10125, 19683, 20736, 34300, 35937, 36125, 46656, 59319, 74088, 81000, 123823, 125000, 157464, 185193, 268912, 279936, 328509, 373248, 421875, 431244, 469567, 474552, 481474, 512000, 592704, 658503, 795906, 804357

Offset: 1

Colin Barker, Jan 30 2014

			2592 is in the sequence because the digital sum of 2592 is 18, and 2592^2/18 = 373248 = 72^3.

Cf. A007953, A236748, A236750, A236751.

s=[]; for(n=1, 100000, d=sumdigits(n); if(n^2%d==0 && ispower(n^2\d, 3), s=concat(s, n))); s

cp's OEIS Frontend

A236750 Positive integers k such that k^3 divided by the digital sum of k is a square.

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A236751 Positive integers n such that n^3 divided by the digital sum of n is a cube.

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Author

Keywords

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Programs

PARI

A236749 Positive integers n such that n^2 divided by the digital sum of n is a cube.

Views

Author

Keywords

Examples

Crossrefs

Programs

PARI