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 A053547 Smallest prime starting with A000422(n). 2
 11, 211, 3217, 432121, 543217, 65432117, 76543217, 876543211, 9876543211, 1098765432101, 11109876543211, 12111098765432101, 1312111098765432139, 141312111098765432113, 15141312111098765432173 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..100 EXAMPLE a(6)=65432117 is smallest prime beginning with the string 654321. MATHEMATICA Flatten[Select[Join[10 #+Range[1, 9, 2], 100 #+Range[1, 99, 2]], PrimeQ, 1]&/@ Table[FromDigits[Flatten[IntegerDigits/@Range[n, 1, -1]]], {n, 25}]] (* Harvey P. Dale, Nov 04 2011 *) PROG (Python) from sympy import isprime def A053547(n): s = int(''.join(str(m) for m in range(n, 0, -1))) for i in range(1, 10): s *= 10 for j in range(1, 10**i, 2): x = s+j if isprime(x): return x else: return 'search limit reached.' # Chai Wah Wu, Jan 02 2015 CROSSREFS Cf. A000422. Sequence in context: A136307 A249604 A038399 * A053582 A077714 A089567 Adjacent sequences: A053544 A053545 A053546 * A053548 A053549 A053550 KEYWORD easy,nice,nonn,base AUTHOR Enoch Haga, Jan 16 2000 STATUS approved

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Last modified June 23 11:27 EDT 2024. Contains 373644 sequences. (Running on oeis4.)