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 A154561 Primes resulting from (sum of digits of k) + (sum of digits of prime(k)) as k runs through the positive integers. 1
 3, 5, 11, 7, 13, 17, 23, 13, 23, 23, 13, 17, 23, 29, 19, 17, 29, 23, 17, 19, 23, 29, 23, 19, 31, 23, 17, 19, 29, 31, 31, 23, 11, 19, 19, 17, 19, 23, 17, 17, 17, 23, 29, 31, 23, 29, 23, 13, 19, 19, 31, 23, 23, 17, 11, 31, 23, 13, 23, 29, 23, 29, 29, 19, 23, 31, 37, 29, 37, 17 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE k=1 yields a term: prime(1) = 2 and 1 + 2 = 3 is prime, so a(1)=3; k=2 yields a term: prime(2) = 3 and 2 + 3 = 5 is prime, so a(2)=5; k=3 does not yield a term: prime(3) = 5 and 3 + 5 = 8 is composite; k=4 yields a term: prime(4) = 7 and 4 + 7 = 11 is prime, so a(3)=11; k=5 yields a term: prime(5) = 11 and 5 + 1 + 1 = 7 is prime, so a(4)=7. MAPLE A007953 := proc(n) add(d, d=convert(n, base, 10)) ; end proc: for n from 1 to 300 do a := A007953(n) +A007953(ithprime(n)) ; if isprime(a) then printf("%d, ", a ) ; end if; end do: # R. J. Mathar, May 05 2010 MATHEMATICA sod[n_]:=Total[IntegerDigits[n]]; Select[Table[sod[n]+sod[Prime[n]], {n, 300}], PrimeQ] (* Harvey P. Dale, Dec 11 2012 *) CROSSREFS Cf. A000040. Sequence in context: A046228 A132162 A168323 * A073653 A225487 A145398 Adjacent sequences:  A154558 A154559 A154560 * A154562 A154563 A154564 KEYWORD nonn,base AUTHOR Juri-Stepan Gerasimov, Jan 12 2009 EXTENSIONS Corrected from a(35) onwards by R. J. Mathar, May 05 2010 Name corrected and Example section edited by Jon E. Schoenfield, Feb 11 2019 STATUS approved

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Last modified June 15 04:47 EDT 2021. Contains 345043 sequences. (Running on oeis4.)