A228586 Write the semiprimes backwards in base 10 and juxtapose (concatenate) their digits.
4, 6, 9, 0, 1, 4, 1, 5, 1, 1, 2, 2, 2, 5, 2, 6, 2, 3, 3, 4, 3, 5, 3, 8, 3, 9, 3, 6, 4, 9, 4, 1, 5, 5, 5, 7, 5, 8, 5, 2, 6, 5, 6, 9, 6, 4, 7, 7, 7, 2, 8, 5, 8, 6, 8, 7, 8, 1, 9, 3, 9, 4, 9, 5, 9, 6, 0, 1, 1, 1, 1, 5, 1, 1, 8, 1, 1, 9, 1, 1, 1, 2, 1
Offset: 1
Examples
4, 6, 9, 01, 41, 51, 12, 22, 52, 62, 33, 43, 53, 83, 93, 64, 94, 15, 55,...
Links
- A. H. Copeland and P. Erdős, Note on normal numbers, Bull. Amer. Math. Soc. 52 (1946), pp. 857-860.
Programs
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PARI
print1(4); for(n=6, 121, if(bigomega(n)==2, d=Vecrev(digits(n)); for(i=1, #d, print1(", "d[i])))) \\ Charles R Greathouse IV, Feb 06 2015
Comments