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 A069847 Number of distinct primes obtained by inserting a 6 at all possible places in n. This includes prefixing. 10
 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,13 LINKS Antti Karttunen, Table of n, a(n) for n = 1..20000 EXAMPLE See the example in A069842. MATHEMATICA Table[ Count[ PrimeQ[ Union[ FromDigits /@ Table[ Insert[ IntegerDigits[n], 6, j], {j, 1, Floor[ Log[10, n] + 2]}]]], True], {n, 1, 105}] PROG (PARI) A069847(n) = { my(digs=digits(n), u=#digs, nums=Set([])); for(n=1, 1+u, nums = setunion(nums, [fromdigits(vector(1+u, i, if(in, digs[i-1], 6))))])); #select(isprime, nums); }; \\ Antti Karttunen, Aug 23 2019 CROSSREFS Cf. A069842, A069843, A069844, A069845, A069846, A069848, A069849, A069850 and A069851. Sequence in context: A104194 A292261 A035153 * A238532 A097249 A112313 Adjacent sequences:  A069844 A069845 A069846 * A069848 A069849 A069850 KEYWORD base,nonn AUTHOR Amarnath Murthy, Apr 16 2002 EXTENSIONS Edited and extended by Robert G. Wilson v, Apr 18 2002 STATUS approved

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Last modified November 29 10:03 EST 2021. Contains 349416 sequences. (Running on oeis4.)