A355439 Smallest Lucas number beginning with n.
1, 2, 3, 4, 521, 64079, 7, 843, 9349, 103682, 11, 123, 1364, 141422324, 15127, 167761, 17393796001, 18, 199, 20633239, 2139295485799, 2207, 23725150497407, 24476, 2537720636, 263115950957276, 271443, 28143753123, 29, 3010349, 312119004989, 322, 33385282, 3461452808002, 3571
Offset: 1
Links
- Michael S. Branicky, Table of n, a(n) for n = 1..1381
- Ron Knott, Every number starts some Fibonacci Number, The Mathematical Magic of the Fibonacci Numbers.
Programs
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PARI
L(n) = real((2 + quadgen(5)) * quadgen(5)^n); \\ A000032 isok(k, dn) = my(dk=digits(L(k))); if (#dk >= #dn, Vec(dk, #dn) == dn); a(n) = my(k=0, dn=digits(n)); while (!isok(k, dn), k++); L(k);
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Python
def aupton(nn): ans, f, g, k = dict(), 2, 1, 0 while len(ans) < nn: sf = str(f) for i in range(1, len(sf)+1): if int(sf[:i]) > nn: break if sf[:i] not in ans: ans[sf[:i]] = f f, g, k = g, f+g, k+1 return [int(ans[str(i)]) for i in range(1, nn+1)] print(aupton(35)) # Michael S. Branicky, Jul 08 2022
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