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A333356
Terms describing the nonprime digits' positions in the way explained in the Comments section.
1
11, 21, 41, 54, 61, 84, 96, 101, 118, 124, 139, 146, 151, 160, 171, 181, 191, 208, 211, 234, 241, 269, 271, 284, 296, 301, 321, 331, 346, 350, 361, 381, 391, 408, 411, 421, 439, 441, 460, 478, 491, 501, 534, 554, 561, 586, 599, 621, 648, 654, 679, 686, 700, 711, 741, 771, 794, 806, 830, 856, 861, 888
OFFSET
1,1
COMMENTS
"11" must be read: "At position 1, there is a 1". And indeed, there is, when considering the sequence as a string of concatenated digits;
"21" reads: "At position 2, there is a 1" - which is true;
"41" reads: "At position 4, there is a 1" - which is also true;
"54" reads: "At position 5, there is a 4" - which is also true;
...
"101" reads: "At position 10, there is a 1" - which is true (the 1 in 61); etc.
We don't read the 2 of 21 as this 2 is a prime digit. Thus 32 and 75 are not in the sequence.
LINKS
CROSSREFS
Cf. A333234 (nonprimes describing the nonprime digits' positions), A264646 (n concatenated with the n-th digit of S).
Sequence in context: A215968 A064832 A129638 * A127624 A097616 A146150
KEYWORD
base,nonn
AUTHOR
Carole Dubois and Eric Angelini, Mar 15 2020
STATUS
approved