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A155913
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Primes p such that (sum of digits of p) - (last digit of p) is prime.
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1
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23, 29, 31, 37, 53, 59, 71, 73, 79, 113, 127, 149, 163, 167, 211, 233, 239, 251, 257, 293, 307, 347, 349, 383, 389, 419, 431, 433, 439, 479, 491, 499, 503, 509, 521, 523, 563, 569, 587, 613, 617, 619, 653, 659, 673, 677, 701, 709, 743, 761, 769, 839, 853, 857
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
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FORMULA
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Presumably a(n) ~ n log n log log n. - Charles R Greathouse IV, Jan 02 2013
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EXAMPLE
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113 is in the sequence because it is prime and its sum of digits (1+1+3 = 5) - final digit(3) is prime (5-3 = 2).
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MAPLE
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A007953 := proc(n) add(d, d=convert(n, base, 10)) ; end: A010879 := proc(n) n mod 10 ; end: for i from 1 to 300 do p := ithprime(i) ; if isprime(A007953(p)-A010879(p)) then printf("%d, ", p) ; fi; od: # R. J. Mathar, Jan 31 2009
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MATHEMATICA
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Select[Prime[Range[200]], PrimeQ[Total[IntegerDigits[#]] - Last[IntegerDigits[#]]] &] (* Vladimir Joseph Stephan Orlovsky, Feb 15 2012 *)
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PROG
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(PARI) is(n)=isprime(sumdigits(n) - n%10) && isprime(n) \\ Charles R Greathouse IV, Jan 02 2013
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CROSSREFS
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Cf. A000040.
Sequence in context: A049483 A112681 A078500 * A227919 A240898 A244077
Adjacent sequences: A155910 A155911 A155912 * A155914 A155915 A155916
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KEYWORD
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nonn,base
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AUTHOR
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Juri-Stepan Gerasimov, Jan 30 2009
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EXTENSIONS
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Corrected by R. J. Mathar, Jan 31 2009
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STATUS
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approved
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