A385145 Integers without 0 as a digit, with an odd number of digits, that are not repdigits, and such that the 2 products [d_1 d_2...dk]*[d_k+1 d_k+2...d_2k+1] and [d_1 d_2...d_k+1]*[d_k+2 d_k+2...d_2k+1] are equal.

164, 195, 265, 498, 16664, 19995, 21775, 24996, 26665, 49998, 1249992, 1666664, 1999995, 2177775, 2499996, 2666665, 4999998, 124999992, 166666664, 199999995, 217777775, 249999996, 266666665, 499999998, 12499999992, 16666666664, 19999999995, 21777777775, 24999999996, 26666666665

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Satvik Saha, Sohom Gupta, Sayan Dutta, and Sourin Chatterjee, Characterising Solutions of Anomalous Cancellation, arXiv:2302.00479 [math.HO], 2025. See p. 5, a finite subsequence of this sequence.

David A. Corneth, PARI program

Prog

(PARI) isok(k) = my(d=digits(k)); if (!vecmin(d), return(0)); if (#Set(d) == 1, return(0)); if (#d % 2, my(ii = #d\2); my(d1=vector(ii, kk, d[kk]), d2 = vector(#d-ii, kk, d[kk+ii])); ii++; my(d3=vector(ii, kk, d[kk]), d4 = vector(#d-ii, kk, d[kk+ii])); if (fromdigits(d1)*fromdigits(d2) == fromdigits(d3)*fromdigits(d4), return(1)); );
(PARI) \\ See Corneth link

Crossrefs

Cf. A052382.

Sequence in context: A240255 A045006 A245386 * A063354 A240248 A376402

Adjacent sequences: A385142 A385143 A385144 * A385146 A385147 A385148

Keyword

nonn,base

Author

Michel Marcus, Jun 19 2025

Extensions

More terms from David A. Corneth, Jun 19 2025

Status

approved