Three codes could be found in the NL-1331E RESEARCH COMPETITION post on the Investigate Ingress blog.

[1] s8caxs6lx2ov4qni

[2] 2509580835289648289656489815564509

[3] 0j0f2itaeny6oiu7l8s

Code #1

Observations

16 characters with the right amount of numbers for a valid passcode

Spoiler

Make a 4×4 grid

Read in a spiral from the lower left 4

4xxs8calvinq2s6o

Passcode returns invalid. Calvin is Ezekiel Calvin

4xxs8ezekielq2s6o

All numbers, check the range but look at it in a different way

Spoiler

Let’s start by making pairs to see what we are working with

25 09 58 08 35 28 96 48 28 96 56 48 98 15 56 45 09

Look at where numbers should be in the passcode format, they all end with a 5.

Reverse each numbers

52 90 85 80 53 82 69 84 82 69 65 84 89 51 65 54 90

Convert decimal to Ascii

4ZUP5RETREATY3A6Z

Don’t let those extra numbers fool you. The passcode format is there

Spoiler

The zero at the start of the code gives it away. Convert to morse

----- .--- ----- ..-. ..--- .. - .- . -. -.-- -.... --- .. ..- --... .-.. ---.. ...

Swap morse bits

..... -... ..... --.- --... -- . -. - .- .-.. .---- ... -- --. ..--- -.-- ...-- ---

Convert morse to text

5B5Q7MENTAL1SMG2Y3O

Convert 5 & 1 to roman numerals V & I

5bvq7mentalismg2y3o