OEIS - A360497

seq.py

# OEIS sequence id A360497: https://oeis.org/A360497
# 
# Author: Hongwei Jin <[email protected]>
# Date: 2023-07-26

from sympy import isprime
import matplotlib.pyplot as plt
import networkx as nx


seq = [2, 3, 5, 7]

for i in range(9, 10**6, 2):

    s = str(i)

    if set(s) <= set("2357") and sum(map(int, s)) in seq and isprime(i):

        seq.append(i)

print(seq)

# plot the sequence
fig = plt.figure(figsize=(4,4), tight_layout=True)
plt.plot(seq)

# plot the sequence as a directed acyclic graph 
fig = plt.figure(figsize=(4,4), tight_layout=True)

nodes = seq
edges = [(i, sum(int(digit) for digit in str(i))) for i in seq]
DiG = nx.DiGraph(edges)
pos = nx.circular_layout(DiG)
nx.draw_networkx(DiG, pos, with_labels=False, node_size=20)

• Sequence plot in the first 175 numbers
  

• A DAG plot of the sequence above