A162394 Fibonacci numbers (A000045) which are anagrams of Triangular numbers (A000217).

0, 1, 3, 21, 55, 2584, 28657, 2178309, 5702887, 14930352, 102334155, 267914296, 701408733, 2971215073, 4807526976, 7778742049, 12586269025, 32951280099, 225851433717, 591286729879, 1548008755920, 10610209857723, 27777890035288, 72723460248141, 308061521170129, 498454011879264, 806515533049393, 1304969544928657, 3416454622906707

Offset: 1

Author

Claudio Meller, Jul 02 2009

Keywords

• nonn
• base

Examples

			2584 is A000045(18) and is an anagram of 2485 = A000217(70).
28567 is A000045(23) and is an anagram of 67528 = A000217(367).
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..38 (all terms <= 20 digits)

Crossrefs

Cf. A000045, A000217.

Programs

Python

from math import isqrt
from itertools import count, islice
def tris(d): # generator of triangular numbers with d digits
    ilb, lb, ub = isqrt(2*10**(d-1))-1, 10**(d-1), 10**d
    if d == 1: yield 0
    for i in count(ilb):
        t = i*(i+1)//2
        if t < lb: continue
        elif t >= ub: break
        yield t
def agen(): # generator of sequence terms
    yield 0
    f, g, n, adict = 1, 2, 1, dict()
    for d in count(1):
        T = set("".join(sorted(str(t))) for t in tris(d))
        while f < 10**d:
            if "".join(sorted(str(f))) in T: yield f
            f, g = g, f+g
print(list(islice(agen(), 20))) # Michael S. Branicky, Feb 18 2024

Extensions

Edited and extended by Ray Chandler, Jul 09 2009

a(24)-a(29) from Chai Wah Wu, Dec 25 2016