A075806 Differences between adjacent palindromic numbers which are products of an odd number of distinct primes.

1, 2, 2, 4, 55, 35, 30, 20, 30, 10, 31, 60, 31, 40, 20, 10, 51, 40, 20, 61, 40, 11, 40, 81, 30, 20, 10, 10, 122, 10, 40, 32, 220, 330, 220, 451, 660, 451, 220, 781, 660, 341, 220, 110, 220, 110, 11, 220, 220, 440, 451, 220, 110, 110, 110, 451, 220, 220, 220, 341

Offset

1,2

Links

Paolo Xausa, Table of n, a(n) for n = 1..1000

Example

a(1)=3-2=1, a(2)=5-3=2, a(5)=66-11=55.

Maple

test := proc(n) local d; d := convert(n, base, 10); return ListTools[Reverse](d)=d and numtheory[mobius](n)=-1; end; s := []; for n from 1 to 11000 do if test(n) then s := [op(s), n]; end; od; a := [op(2..-1, s)-op(1..-2, s)];

Mathematica

Differences[Select[Range[10000], PalindromeQ[#] && MoebiusMu[#] == -1 &]] (* Paolo Xausa, Mar 10 2025 *)

Crossrefs

Cf. A037010.

First differences of A075800.

Sequence in context: A257618 A088895 A257619 * A295580 A177956 A345758

Adjacent sequences: A075803 A075804 A075805 * A075807 A075808 A075809

Keyword

nonn,base

Author

Jani Melik, Oct 13 2002

Extensions

Edited by Dean Hickerson, Oct 21 2002

Status

approved