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.

A334530 Numbers that are both binary palindromes and binary Smith numbers.

Original entry on oeis.org

15, 51, 85, 471, 765, 771, 843, 951, 1023, 1285, 1501, 1707, 2015, 3687, 3831, 4095, 4369, 4777, 5621, 5917, 6077, 6483, 6643, 6891, 6939, 7003, 7099, 7447, 7671, 10041, 11565, 12093, 13011, 14631, 15063, 15855, 20345, 20473, 22517, 23213, 26067, 26483, 26611
Offset: 1

Views

Author

Amiram Eldar, May 05 2020

Keywords

Examples

			15 is a term since its binary representation, 1111, is palindromic, and its prime factorization, 3 * 5, is 11 * 101 in binary representation, and 1 + 1 + 1 + 1 = (1 + 1) + (1 + 0 + 1).
		

Crossrefs

Intersection of A006995 and A278909.
Cf. A098834.

Programs

  • Mathematica
    binPalSmithQ[n_] := PalindromeQ[(d = IntegerDigits[n, 2])] && CompositeQ[n] && Plus @@ (Last@# * DigitCount[First@#, 2, 1] & /@ FactorInteger[n]) == Plus @@ d; Select[Range[10^5], binPalSmithQ]