A320170 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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