A362020 - OEIS

A362020

Nonnegative numbers k not ending in 0 such that, in decimal representation, the subsequence of digits of k^2 occupying an odd position is equal to the digits of k.

1, 5, 6, 11, 76, 105, 501, 505, 506, 605, 756, 826, 1001, 5941, 10005, 10505, 12731, 13921, 50001, 50005, 50006, 50105, 50501, 50505, 50506, 50605, 60005, 60505, 88705, 100001, 118905, 364231, 592421, 594941, 684006, 1000005, 1000505, 1050005, 1050505, 1355941

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OFFSET

1,2

COMMENTS

Subsequence of A326418. No term starts with the digit 2.

LINKS

Table of n, a(n) for n=1..40.

PROG

(Python)

from itertools import count, islice

def A362020_gen(startvalue=0): # generator of terms >= startvalue

return filter(lambda n:n%10 and n==int(''.join((s:=str(n**2))[len(s)&1^1::2])), count(max(startvalue, 0)))