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 A048853 Number of primes (different from n) that can be produced by altering one digit of decimal expansion of n (without changing the number of digits). 24
 4, 3, 3, 4, 3, 4, 3, 4, 4, 4, 7, 4, 8, 4, 4, 4, 7, 4, 7, 2, 7, 2, 6, 2, 2, 2, 7, 2, 5, 2, 5, 2, 8, 2, 2, 2, 5, 2, 7, 3, 6, 3, 7, 3, 3, 3, 6, 3, 8, 2, 7, 2, 6, 2, 2, 2, 7, 2, 5, 2, 5, 2, 8, 2, 2, 2, 5, 2, 7, 3, 6, 3, 7, 3, 3, 3, 8, 3, 6, 2, 7, 2, 6, 2, 2, 2, 7, 2, 5, 1, 6, 1, 7, 1, 1, 1, 4, 1, 6, 4, 10, 4, 8, 4, 4 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(A192545(n)) = 0. - Reinhard Zumkeller, Jul 05 2011 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE Altering the number 13 gives eight primes: 11, 17, 19, 23, 43, 53, 73, 83, so a(13)=8. MAPLE A048853 := proc(n::integer) local resul, ddigs, d, c, tmp ; resul := 0 ; ddigs := convert(n, base, 10) ; for d from 1 to nops(ddigs) do for c from 0 to 9 do if c = 0 and d = nops(ddigs) then continue ; else if c <> op(d, ddigs) then tmp := [op(1..d-1, ddigs), c, op(d+1..nops(ddigs), ddigs)] ; tst := sum(op(i, tmp)*10^(i-1), i=1..nops(tmp)) ; if isprime(tst) then resul := resul+1 ; fi ; fi ; fi ; od : od ; RETURN(resul) ; end: for n from 1 to 90 do printf("%d, ", A048853(n)) ; od ; # R. J. Mathar, Apr 25 2006 MATHEMATICA a[n_] := Module[{idn = IntegerDigits[n], id, np = 0}, Do[id = idn; If[ id[[j]] != k, id[[j]] = k; If[ id[[1]] != 0 && PrimeQ[ FromDigits[id]], np = np + 1]], {j, 1, Length[idn]}, {k, 0, 9}]; np]; Table[a[n], {n, 1, 105}] (* Jean-François Alcover, Dec 01 2011 *) PROG (Haskell) import Data.List (inits, tails, nub) a048853 n = (sum \$ map (a010051 . read) \$ tail \$ nub \$ concat \$ zipWith (\its tls -> map ((\xs ys d -> xs ++ (d:ys)) its tls) "0123456789") (map init \$ tail \$ inits \$ show n) (tail \$ tails \$ show n)) - a010051 n -- Reinhard Zumkeller, Jul 05 2011 (Python) from sympy import isprime def h1(n): # hamming distance 1 neighbors of n, not starting with 0 s = str(n); d = "0123456789"; L = len(s) yield from (int(s[:i]+c+s[i+1:]) for c in d for i in range(L) if c!=s[i] and not (i==0 and c=="0")) def a(n): return sum(1 for k in h1(n) if isprime(k)) print([a(n) for n in range(1, 106)]) # Michael S. Branicky, Jul 31 2022 CROSSREFS Cf. A050652-A050673. Cf. A010051, A158124. Sequence in context: A026858 A188885 A129344 * A303701 A179845 A180217 Adjacent sequences: A048850 A048851 A048852 * A048854 A048855 A048856 KEYWORD base,nonn,easy,nice AUTHOR STATUS approved

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Last modified December 3 05:56 EST 2022. Contains 358512 sequences. (Running on oeis4.)