cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A334416 Numbers m such that (m / sum of digits of m) is a palindrome.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 18, 21, 24, 27, 36, 42, 45, 48, 54, 63, 72, 81, 84, 110, 132, 198, 220, 264, 330, 396, 440, 550, 594, 605, 660, 715, 770, 792, 825, 880, 935, 990, 1010, 1056, 1188, 1212, 1310, 1386, 1452, 1584, 1782, 1810, 1812, 1815, 1818, 1848
Offset: 1

Views

Author

Bernard Schott, Apr 28 2020

Keywords

Comments

Not to be confused with A114440 whose first 23 terms are identical to the terms of this sequence, while A114440(24) = 108 and a(24) = 110.

Examples

			The number 264 is a term of the sequence because it is divisible by the sum of its digits: 2+6+4=12; 264/12=22 and 22 is a palindrome.

Links

Crossrefs

Cf. A001101 (similar for primes).
Cf. A334417 (resulting palindromic quotients).
Subsequence of A005349 (Niven (or Harshad) numbers).
Subsequence: A276142 (palindromic terms).

Programs

  • Mathematica
    Select[Range[2000], PalindromeQ[# / Plus @@ IntegerDigits[#]] &] (* Amiram Eldar, Apr 28 2020 *)
  • PARI
    isok(m) = iferr(my(d=digits(m/sumdigits(m))); d==Vecrev(d), E, 0); \\ Michel Marcus, Apr 29 2020

A276143 Solutions to x/SOD(x) = y, where x and y are palindromes, a(n)=SOD(x).

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 36, 36, 45, 36, 36, 36, 36, 63, 24, 36, 36, 36, 48, 72, 24, 48, 36, 36, 63, 36, 63, 63, 48, 48, 48, 48, 24, 24, 24, 48, 48, 48, 48, 36, 36, 36, 36, 48, 48, 48, 48, 48, 48, 48, 48, 48, 72, 24, 24, 48, 48, 48, 48, 48, 48, 48, 48, 48
Offset: 1

Views

Author

Lars Blomberg, Aug 22 2016

Keywords

Comments

"SOD" = "sum of digits" (A007953).

Examples

			279972/SOD(279972) = 279972/36 = 7777, so 36 is a term.

Links

Crossrefs

See A276142 for the x values.
See A276144 for the y values.
Cf. A002113, A007953.

A276144 Solutions y to x/SOD(x) = y, where x and y are palindromes.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 7777, 77077, 122221, 707707, 770077, 7070707, 7700077, 4444444, 88888888, 70077007, 70700707, 77000077, 88888888, 88888888, 888808888, 488888884, 700707007, 707000707, 404444404, 770000077, 440444044, 444040444, 848888848, 884888488
Offset: 1

Views

Author

Lars Blomberg, Aug 22 2016

Keywords

Comments

"SOD" = "sum of digits" (A007953).

Examples

			279972/SOD(279972) = 279972/36 = 7777, so 7777 is a term.

Links

Crossrefs

See A276142 for the x values.
See A276143 for the SOD(x) values.
Cf. A002113, A005349, A007953.
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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