A320170 Every pair of consecutive numbers sums to a palindrome, starting with a(0)=1; a(1)=10, and taking a(n) = smallest number > a(n-2).

1, 10, 12, 21, 23, 32, 34, 43, 45, 54, 47, 64, 57, 74, 67, 84, 77, 94, 87, 104, 98, 114, 108, 124, 118, 134, 128, 144, 138, 154, 149, 164, 159, 174, 169, 184, 179, 194, 189, 204, 200, 214, 210, 224, 220, 234, 230, 244, 240, 254, 251, 264, 261, 274, 271

Offset

0,2

Links

Table of n, a(n) for n=0..54.

Mathematica

Nest[Append[#, Block[{k = #[[-2]] + 1}, While[! PalindromeQ[#[[-1]] + k], k++]; k]] &, {1, 10}, 53] (* Michael De Vlieger, Oct 10 2018 *)

Prog

(Python)
CurrentNum=10
PreviousNum=1
NewNum=0
def NextPalindrome(StartNum):
    FoundNext=0
    t=0
    n=0
    Number=0
    Lastdigit=0
    while FoundNext<=PreviousNum:
        n=n+1
        t=StartNum+n
        Number=t
        Reverse=0
        while Number>0:
            Lastdigit=Number%10
            Reverse=(Reverse*10)+Lastdigit
            Number=Number//10
        if t==Reverse:
            FoundNext=n
    return n
print(1)
print(10)
for x in range(50):
    NewNum=NextPalindrome(CurrentNum)
    print(NewNum)
    PreviousNum=CurrentNum
    CurrentNum=NewNum

Crossrefs

Cf. A062932.

For n < 10, equals A061870 and A175885.

Sequence in context: A368550 A337866 A357045 * A082927 A108965 A366958

Adjacent sequences: A320167 A320168 A320169 * A320171 A320172 A320173

Keyword

nonn,easy,base

Author

Jim Singh, Oct 07 2018

Status

approved