A075801 Differences between adjacent palindromic nonprime numbers A032350.
3, 2, 2, 1, 13, 11, 11, 11, 11, 11, 11, 11, 12, 10, 20, 20, 10, 31, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 20, 10, 10, 20, 30, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 10, 20, 10, 20, 10, 31
Offset: 1
Examples
a(1)=4-1=3, a(5)=22-9=13.
Programs
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Maple
test := proc(n) local d; d := convert(n,base,10); return ListTools[Reverse](d)=d and not isprime(n); end; s := []; for n from 1 to 1000 do if test(n) then s := [op(s),n]; end; od; a := [op(2..-1,s)-op(1..-2,s)];
Extensions
Edited by Dean Hickerson, Oct 21 2002