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A100763 a(1) = 2; for n>1, a(n) is the least prime with all prime digits which is == 1 (mod a(n-1)). 0
2, 3, 7, 337, 32353, 7727255227, 23523352753755575323 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(7) > 2*10^19. - Robert G. Wilson v, Nov 27 2004

a(8) > 2*10^32. - Jon E. Schoenfield, Mar 29 2015

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

a(4) = 337, a(5) = 32353 == 1 (mod 337).

MATHEMATICA

a[1] = 2; a[n_] := a[n] = Block[{k = 1, p = a[n - 1]}, While[ !PrimeQ[k*p + 1] || Union[ Join[{2, 3, 5, 7}, IntegerDigits[k*p + 1]]] != {2, 3, 5, 7}, k++ ]; k*p + 1]; Table[ a[n], {n, 6}] (* Robert G. Wilson v, Nov 27 2004 *)

CROSSREFS

Sequence in context: A079637 A062662 A084727 * A132538 A062615 A180162

Adjacent sequences:  A100760 A100761 A100762 * A100764 A100765 A100766

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Nov 25 2004

EXTENSIONS

a(6) from Robert G. Wilson v, Nov 27 2004

a(7) from Jon E. Schoenfield, Mar 29 2015

STATUS

approved

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Last modified January 20 21:36 EST 2019. Contains 319336 sequences. (Running on oeis4.)