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A069846 Number of distinct primes obtained by inserting a 5 at all possible places in n. This includes prefixing. 9
0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,21

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

See the example in A069842.

MATHEMATICA

Table[ Count[ PrimeQ[ Union[ FromDigits /@ Table[ Insert[ IntegerDigits[n], 5, j], {j, 1, Floor[ Log[10, n] + 2]}]]], True], {n, 1, 105}]

CROSSREFS

Cf. A069842, A069843, A069844, A069845, A069847, A069848, A069849, A069850 and A069851.

Sequence in context: A288318 A219483 A239927 * A239657 A298934 A309061

Adjacent sequences:  A069843 A069844 A069845 * A069847 A069848 A069849

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 March 31 03:48 EDT 2020. Contains 333136 sequences. (Running on oeis4.)